MAC1 USFT Analysis/Overview

Yep, great review as usual Cole! 

I remember back when you got your USFT that you started winning FT matches much more often than with the previous guns you used! I might have had some influence on your purchase decision which I might regret a little, lol. Just kidding.

I don't think a more solid air rifle has ever been made than the good ole USFT. Mine has been nothing short of phenomenal in precision and reliability for almost two decades. But as I age I'm finding mine starting to get a bit heavy in offhand which is one reason I decided to sell it. Well the other reason is I want a lighter weight Thomas FT rig to go with my HPX EFT rig.

Shameless plug - it's in the classifieds for all you USFT hopefuls.

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Thanks Steve.

Yep, the wins came with the USFT, although I'd shot an HW77k quite a bit prior to getting the USFT. Ahhh springers. Exercises in frustration. 

Yep again, you and Bobby were highly influential in my decision to get this gun. 

Yep with the rest too, SOLID air rifle, and not on the light side. I'd be curious to know the weight difference between a typical Thomas (not your Surely as she's kind of a unique situation) and the USFT. 

Great start Franklink.

For info, there were 7 Simple Simons. Tim MacMurray has #7, afik. Not sure who else has one or if LD kept any of the 7 for himself. Wish I had picked one up but didn't really have the money handy. Steve Schultz used one to win the Nationals the year after they were built, I believe. Others have won the Nationals with the production USFT's as well but I don't have a current talley. In the first run, we were allowed to pick our sn and I ended up with 25 but it was around 14th to be built. Each of the early ones were tuned and tested by LD in his tunnel.

My barrel shot well in the tunnel but was pretty wind sensitive. After a few years of struggling with that, I finally replaced it and would say it's on par w Franklink's, but his is tuned SO much nicer. Haven't touched the zero in an unknown number of years, and have yet to replace an oring in 19 years of use. The only issue ever besides the barrel was the fill port valve ... which was an easy replacement .

Great rifles... cudos to LD and TimMac.

Bob

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Thanks Bobby, was hoping you'd chime in with the real #s as my memory was a bit fuzzy there. 

They do have quite the track record for wins. 

19 years without even an oring! Gotta be some sort of record for a PCP. I think I remember Steve saying something similar about his. I just did some digging and figured out that I received mine in October of 2018, much shorter time frame but so far mine is on track as I haven't needed an oring or any other sort of work to keep it running. 

The barrel...

An airgun simply has to have a good barrel to be able to shoot well. It's also imperative that that good barrel be affixed to the gun in a stable manner if consistent point of impact/scope zero is of concern. USFT's use 16mm Lothar barrels as a standard. Tim apparently used some sort of custom barrel with a very minimal number of lands and grooves at some point early on (1 or two grooves? maybe Bobby can help with the details again here). When I ordered mine he told me that he also had gotten some really good shipments of HW barrels that went into the USFTs for awhile, but that the most consistent/best performing barrels he can get now are Lothars. So, mine has a 16mm polygonal .177 Lothar. Tim has had the "slow polys" advertised on his website and I'm curious if mine has it, or a regular twist. I guess the slow polys are 1:36 and the standard poly is a 1:17.7. I've never measured mine to know, but regardless of what it has in it, it will not be changed any time soon, as it shoots incredibly accurately. Mine also has a very gentle choke. 

Barrel attachment....

The barrel is held inside the breech by means of 4 large diameter bolts that come up through the baseplate at the bottom of the gun, through the tube, and through the threaded breech. As usual, this is an atypical airgun design feature so here are some photos to help visualize.

The two phillips head screws to the left here hold the uit rail to the wood block, but the two right phillips hold the rail/block to the gun. (referring to the 4 phillips head screws in the bottom of the Anschutz rail)



Removing the two phillips screws on the right allow the block to come off the gun, and gains access to the four breech bolts (black headed allen bolts here).



The next couple of pictures show those four bolts, each a couple of inches long, going up through base plate, tube, and breech.



This is the extra barrel in .22 that I asked Tim to send with my gun when I ordered it. The unblued portion is the section of barrel that is held by the breech.



The breech is effectively a giant vise and an EXTREMELY reliable means of keeping a barrel in the same place which = 100% reliable maintaining of scope zero. We're talking about scope zeros that maintain for literal YEARS. Rare in an airgun. 

So how does the aluminum breech block open enough to clamp the barrel?

A big diagonal slit



Reduction of the clamping force of the breech on the barrel is mostly done by the two bolts on the same side as the slit, but the two on the opposite side of slit opening also have to be loosened slightly (at least on mine) to be able to pull the barrel. 

Because I ordered two barrels, Tim provided some hand-written directions on how to replace a barrel on a USFT, in his words:

"For swapping barrels the air can be left in the gun.

To swap barrels: Remove forearm fasteners and remove wood. Loosen two large action fasteners on right hand side of lower base plate 2 turns. Make sure transfer port is closed. Hold barrel so it wont slide out. Witness mark barrel being removed at slit in barrel mount to preserve scope data. Slide barrel out of gun and slide replacement barrel in. Support muzzle by work surface with gun vertical. Pull down on grip and tighten large action fasteners. Test tension of transfer port/breech to barrel fit and adjust for engagement. Transfer port to barrel tension must be set with air charged gun."

Here is the witness mark (in blue) I added to my .177 barrel so that it can easily be returned to the same location if ever removed.



While I'm talking about the barrel, here is one of the really user friendly features of the design.....

After removing the cheekpiece by means of the single silver allen head bolt here



Completely unfettered access to the rear of the barrel is achieved, talk about easy cleaning!!! (well I guess you gotta cock the gun to get the hammer out of the way, but still, easy-peasy compared to most guns)



Here is the leade and crown of the .22 barrel



I ordered the extra barrel as I envisioned swapping back and forth and getting multiple uses out of the gun. In reality, this became one of a couple attempts I made at having multiple barrels for the same gun with the rose colored glasses idea of swapping back and forth. It took my stubborn self a while to learn that, while good on paper/in principle, in practice the more than one barrel for a gun concept is a poor one. Going back and forth between barrels and scope settings gets old quickly. I ultimately ended up buying a different .22 gun and it was for the better. The USFT just shoots so good as my dedicated/hard-core field target gun, and maintains all zero and thereby the dope data so well, that it's really a disservice to the gun, it's design, and intended use to be switching back and forth all the time. Rezeroing after barrel swaps simply defeats the purpose of all the unique engineering that creates such a stable point of impact. 

As for the .177 poly that lives in the gun, there was a bit of a learning curve to it in those first few months of ownership. In the beginning it had a bad habit of accuracy degredation after not very many shots, 100-200 if I remember right. I could clean it after that and it'd go back to shooting really good, but another 100-200 shots and it'd start to open up a bit. Arzrover suggested a couple things. First was to JB bore paste the barrel to polish it up as much as possible. So I did that. He also suggested Slick 50 One lube. So I started washing and lubing my pellets. Perhaps it was just the barrel getting leaded up, or a combination of barrel break-in, JB Bore Paste, and cleaned/lubed pellets, but I've yet to have the accuracy degradation that I saw early on. I'll typically clean it after a tin of pellets now, but I've gone more than two tins without cleaning since the above recipe was arrived at and it still shoots well after 1000 pellets. And cleaning is simple (and unorthodox). I just push a couple qtips through the barrel, from the breech end. I'll usually wet them with the same Slick 50 one lube. The first one or two usually has a little bit of black on it, and then they're clean as a whistle. Cleaning may be more of a superstition than anything else at this point, but it shoots so well with the above prescription that I'm not changing anything, (even it is is simply superstition).

"Tuning"

That word means a lot of different things to us all, I'm going to use it primarily to refer to the power level and balance of the gun. 

The power level/balance of the USFT can be adjusted/optimized through three main processes: hammer tension, transfer port restriction, and hammer weight. But, as the trend goes with this gun, some of these are a little unorthodox. 

Hammer tension: pretty straight forward here, remove the cheekrest to access the allen key that increases/decreases the hammer tension. I view this as the coarse adjustment.



Transfer port restriction: this was not an option on the earliest USFTs but later specimens have a small grub screw in the back of the transfer port that restricts airflow through obstruction, further "in" equals reduction of power. Circled in red here (The white is a little bit of teflon as insurance to keep it from moving). This is more of a fine tuning of the amount of air that hit's the pellet (power output). 



And the third mechanism to adjust the power: adding weight to the hammer. Again, early USFTs did not have this feature, but later specimens have a 1/4x20 threaded hole in the hammer into which bolts of various weights can be added to increase the force with which the hammer hits the transfer port. A roughly 1 and 1/4 inch long socket head bolt shown here threaded into that hole to illustrate the process. 



Mine came from Tim tuned to shoot the 13.43gr JSB .177 pellets. I found it to shoot REALLY well with 10.34s so I needed to do a bit of adjustments to the hammer tension and the port restrictor. I'll get into shot strings later, but the final tune makes for a a really smooth and efficient shooter. Playing with hammer tension and port restriction settings allowed me to find a balance where the gun sounds and feels happy, with chrono #s to support that impression. 

For a field target legal power level I didn't need to add any weight to the hammer. I did, however, play with the .22 barrel in the first couple months of ownership of the gun. For that I did add weight to the hammer. That screw in the hammer in the photo above was used to get the gun up to around 30fpe without any changes to the hammer tension or port restriction as I knew I was going back to .177/20 fpe and didn't want to lose the settings. The 30fpe was with 18.13grain .22s. I also used these two bolts to play with 15.89s and 13.43s. I think the shortest is 3/4inch long and the middle length is 1 inch. From memory the 3/4 inch long bolt got the 13.34 .22s into the 23fpe realm, with the 15.89s around 26fpe. Accuracy from all three pellets and their respective power levels at 60 yards and groups were in the 1 inch area with all three. So, average, and maybe even "good" accuracy, but nothing spectacular from the .22 barrel. I was mostly interested in seeing the effect of the bolts as hammer weight, and whether or not that .22 barrel could shoot so I didn't do any shot strings or efficiency data, knowing full well that I was going back to .177 and field target legal power levels. 

I suppose further weight could be added by putting nuts on the bolts but I never went that deep into the experiment. Also, upping the hammer tension in addition to the weights is likely to yield even greater fpe. I'm a little curious to know how high it could go, but not enough to undo the field target settings the gun lives in. (Confidence is big for competition. I've got a lot of confidence in the tune and don't want to mess with it. I'm sure I could get it back where it is, but I'd rather not need to build confidence in it all over again). 

Furthermore on the power adjustments, Tim included an extra valve stem/poppet. Seen here:



(also seen here and supplied with the gun is an extra burst disc, some extra orings (seals swing breech to the barrel I believe), and an extra "foot" which is essentially just the sacrificial piece of metal within the kneeriser that exerts pressure on the opposite rail when tightened-keeps the bolt from marring the trough of the Anschutz rail. Oh, and a patch.

So, for really serious/curious tuning, Tim sent a note with my gun that says, "0.2fpe per 0.001" diameter of valve head." I'm not sure if he meant the valve stem can be reduced by 0.001" to gain 0.2fpe or if the outer diameter of the delrin has to be reduced by that much to gain 0.2fpe. My gun is going to stay at its just under 20fpe power level so I won't every be testing out this theory, just thought I'd include it for any interested parties. 

Great job Cole!

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Thanks John.

I had one, sold it to buy the Thomas L. Love the "L" but deeply regret selling the USFT

But I caught a guy selling his (#207) in late June, he took delivery in Jan '21 so its almost brand new. Havent had time to get it sorted out yet.



Butt ugly guns, but cool in that same sense. Remember: the target does not care what yer gun looks like



Dunno how true this is but Ive heard that Mac-1 has the receivers made in batchs (including the anodizing) and the numbers on them are not a sequential production number, just the number thats on the, say, red one. 

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A bunch of us ft shooters/friends here in AZ saw that one come up on the yellow and wondered who ended up with it. More than one of us was considering buying it ourselves. We tried really hard to talk a new to FT shooter into it. This is the one that looks very similar to mine right? A Cali friend of mine contacted the seller and I guess some internal changes were made by the guy after he got it but what was done I do not know. 

lol, yep those dropped field targets don't care how ugly the gun is 

Tim made some comments on the phone when I ordered the gun that support the made in batch's concept. I got the impression that either when funds allow, or when he's taken enough deposits, he has a batch of parts made by whoever he outsources the machining to. I think he has to do some final shaping of the parts too, as mine has some sign's of post-machining fitment here and there, just like anything that's handmade/not commercially manufactured will have. (I remember reading a few years ago about a guy that bought one and went to Tim's shop to watch him put it together. The guy wrote that he was surprised at how much force was required to fit some of the parts-hammering pins in place and such-and just overall how tight the tolerances were for the parts to come together to make a finished gun). I have no idea if the batched machining relates to how they get numbered though. If he hasn't kept track of what numbers have been used, and just has the anodizer throw some random numbers on the breech, then who knows how many have been made. Anybody else have a #165? ha ha

Efficiency

For me, the "magic" of the USFT comes from its low fill pressures. This post will address this novelty in the PCP world.

When most of us take the leap into PCPs we find ourselves questioning how we're going to fill them. If it's been too long for you to remember that stage of the hobby, just take a look at any given moment on any of the forums and you'll find guys asking about pumps, compressors, tanks, fittings, fill stations, etc, as they try to figure out what is going to work best for them and their needs and wants. Occasionally we get somebody asking about 3000 psi SCUBAs, and very frequently we get guys asking about hand pumps. The typical responses to both are "NO WAY, can't even fill a PCP one time with a 3000 SCUBA," and, "ha ha, enjoy the hand pump to 250-300 bar, snort." For most guns, those responses are fairly appropriate as you truly can't fill a PCP with a +3000psi (207 bar) max fill pressure even once with a 3000 SCUBA tank, and hand pumps do really suck (suck the fun out of it) for filling high pressure guns. And the trend seems to be moving towards even higher and higher fill pressures. 

Enter the tubed version of the USFT. There's a slight variation in the fill pressure that most tubed USFT's prefer to run at, but most that I've been around (mine and friend's guns) seem to like to fill up to around 1500psi. My personal example does really well with filling to 1450psi, and shooting down to 1250psi. A PCP operating in those pressure ranges is truly an oddball in the PCP world. For example, consider that many guns have 250 bar fill pressures (3626psi) and the USFT fills to only 1450, that's a difference of 2176psi! So, it's got to be a weak little 6fpe-producing 10m gun right? Nope. Mine does right under 20fpe to make it field target legal. LD recently shared here on AGN somewhere that he shot a highly modified USFT up at the long range airgun competition in Oregon a few months ago. That was a .22 shooting the MRDs (25.4grs) at around 50fpe if I remember the details correctly, and still a low fill pressure gun. I can't remember the top end he was filling to, and he may not have even said, but really impressive to get that kind of power from such a low pressure. (LD, feel free to chime in with the details on that Oregon gun, and I'd love to hear your secrets on to get such high power from such low psi.)

I've been meaning to shoot a current shot string over the chrono but have just been too busy so I'm recycling the #s from this post:

https://www.airgunnation.com/topic/usft-unregulated-shot-string/

I don't expect much variation in current fps numbers from those that I shot a few years ago, as I haven't needed to touch much. I very vaguely remember giving the transfer port resctrictor something like 1/16th of a turn "in" but I'm still using the same dope sheet from this old string and all the impact points match, so it didn't change much. Maybe I'll still shoot a string over the chrono if I get time, just to see what's changed since 2019.

Here is the breakdown from that recycled 2019 string. 





I intentionally overfilled, and shot down past the 1250psi, just for the sake of collecting data. (The break in the plotted line was an error in the chrono).

The gun is good for a very consistent 40 shots and actually more than that throughout a match as the temp increases. I've shot 48 shot matches without refilling. The rising temp throughout a morning increases the tube pressure enough to get some extra shots. I've also had the opposite happen to me, with decreasing temps the gun will lose a few shots. The important thing is that I know if the gauge is between 1450 and 1250, I can 100% trust the fps to be consistent enough to have complete faith in where the pellet is going to impact at various distances. 

Here's the efficiency numbers, not too bad, 1.28fpe/cu inch per shot-puts it in Lloyds "good" category. (thanks to Lloyd Sikes for making these calculators available for general public use). 



So, how big is that tube?



The air holding portion of the tube looks to be 19-20.5 inches long. I'm not sure where the end piece stops at the rear of the tube.



Outer diameter of mine is about 1.995in or 5.07cm. 

Arzrover measured the inner diameter of the tubes to be 4cm. That gives wall thicknesses of just a bit over 1cm if you're curious. And using good ole V=(pie)(r squared)h for volume of a cylinder, we're looking at a volume of around 640ccs (using radius=2cm and height = 50.8cm or 20 inches). 

640cc giving 40 good consistent shots from 1450 to 1250psi. 

I started out thinking this was going to be my last PCP (lol to that one, 5 or 6 other PCP's later), so I invested in a heavy 80cf, 3000 PSI SCUBA tank. It proved to be too big and heavy for mobility so I bought a slender little 19cf tank, also 3000 psi, to use as a sort of buddy bottle for my USFT. Eventually I wanted some more PCPs so ended up with an 87cf SCBA carbon fiber tank too.

Here are the numbers for those 3 tanks.





 

The little 19cf SCUBA is about 4 inches in diameter and about 19 inches long. It's about the size of a silver and green oxygen bottle that you see people carting around. With that little 19cf tank I can fill the gun 31 times, @ 40 shots per fill, that's 1240 shots, or, nearly 2.5, 500 count tins. LOTS of shots.

The 80cf SCUBA gives 130 fills, @ 40 shots per fill, that's 5200 shots, or nearly 10.5, 500 count tins. LOTS and LOTS of shots. 

The 87cf SCBA gives 186 fills, @ 40 shots per fill, that's 7440 shots, or nearly 15, 500 count tins. LOT and LOTS and LOTS of shots. 

Now, that's all theoretical numbers, and I've never ONLY filled the USFT from the big 80cf SCUBA or the SCBA so cant verify anything there, but I have filled ONLY the USFT from the 19cf smaller SCUBA and I can verify that it will shoot more than 2 tins of pellets through it before the pressure gets down to lower than 1250psi. So, the #s LLoyd's calculator predicts for the bigger tanks seem plausible. 

What all that means, is that for somebody who doesn't need more than 20fpe, the USFT can shoot and shoot and shoot and shoot with one fill from a simple ole 3000psi SCUBA tank. This makes the chasing of high pressure compressed air much more simple, as true 4500 psi fills in a SCBA are harder to come by than 3000 fills. And if you own the compressor, 3000psi fills are much less wear and tear on equipment than 4500psi fills. 

Furthermore, many of the male fosters on my higher pressure guns eventually end up with ball bearing divots from the inside of the female foster and the pressure exerted on the female foster shoulder. The male foster on my USFT has none of that nonsense, and I don't expect it to ever get that deformation, as 1450psi is simply easier on all the fittings. 

And there's no regulator to ever act wonky. Wink wink.

A true oddity in the airgun world. 

(For those hand pump guys...I did fill the gun one time with a Hill MK3 hand pump, shortly after getting it. From memory it was something like 120pumps from 1250 up to 1450psi, and OH SOOO easy strokes. I used to fill a Benji Discovery up to 1900 with a hand pump and the pump strokes for the USFT made the pump strokes for the Disco seem hard, and even they're not too bad compared to trying hand pump a 250 bar PCP. So, VERY hand pump friendly gun, the tubed USFTs.). 

I've not shared much of the actual accuracy of my USFT, as I just haven't shot it much lately. It's the gun that almost feels like cheating when I compete with it, so for regular monthly matches I've usually been shooting something else (in the past year and a half or so). But this past weekend was the STATE match, so I brought out the serious field target gun..

I love to go and spend a night or two camping and hanging out and shooting and talking airguns and spending time with airgun friends. Something bout sleeping in a tent always makes me wake up with the daylight though. And because of that, I was up pretty early on Friday morning. Decided it'd be a good time for a little reaquainting with the USFT, as I intended to shoot it for the competition on Saturday.

Here's an early morning glamour shot from that brief practice session.



These groups were all from the first 20 or 30 shots that morning.

Off to the left here it took 10-15 shots to get settled into my position, then I shot the 5 shot group on the right. 27 yards from bum bag. .177 pellet sitting there, head up, for size comparison. 



And from that tight 5 shot group above, went straight to my other pellet trap, set at 47 yards, and shot this ten shot group. .177 pellet in the frame again for size comparison. 



The couple shots in the upper right that started to wander away from the center of the rest of them were shooter induced (operator error). 

Shot a bit more that morning but knew the gun would simply do what it does for the comp on Sat.

Went on to shoot 48/52. I think only Lauren Parsons was the only higher first day total than that, at 49. 

My 4 misses were 2 of the 6 offhand shots, and 2 of the 4 kneeling shots. So, the trusty USFT went 42/42 on the field target standard bumbag position shots, and 6/10 on the forced position shots. That says a lot more about myself being out of practice than the gun not performing up to snuff. 

And that was with the same settings and scope zero that the gun had at the previous AZ state match, a year ago. Quite the testament to reliability right there. 

Frank,

Glad you like it. It doesn’t need much care, but I do notice some rust on the hammer strut that can, if left alone begin to cause a little velocity variation due to drag on the side of the hammer.

BTW, all the older guns had an oring “on” (but not inside the bore of course) end of the barrel, and for good reason, since if a pellet stuck out a bit and you close the breech on it, it can damage the o’ring or even pull it loose so it falls on the ground somewhere and leaves you hanging in mid-match if its on the swinging breech, but not so if its on the end of the barrel.

Something you may not know …. The sear hook that catches the hammer can be manually cocked (without pulling the hammer back) and the gun dry-fired like many high end 10M match guns. 

The gun was designed for Field Target, which is what you use it for. The port screw is a useless affectation better left alone (in my opinion), as are the two tiny “adjustment screws” for trigger and sear travel.

If I see you at Morro bay soon, I’ll show you more.



LD

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Yes, I very much like it. Thank you for creating such an amazing airgun. 

As to the rust, when I got it, Tim had some sort of red looking grease on that pin/shaft that holds the hammer to the hammer strut. I'd always just left it alone but your talk of rust had me concerned. It wiped right off with a qtip, some sort of lubricant I think. The strut itself has the color of heat treated steel, as does the sear hook, at least to my eye. Here are some close ups. 

(more visible if screen is maximized)



https://www.youtube.com/watch?v=YxMUmEwU3jw



And you are correct that I had no idea about the ability to bypass the hammer and cock the gun for dry fire practice like 10m guns. Here is that action:



https://www.youtube.com/watch?v=8ae38hqIT08



As for the port screw, once I got it where I wanted it, have not messed with it since. Same for the trigger screws, I've never adjusted them. 

I won't be making it to Morro Bay, but would love to hear more about the gun and its creation at some point. 

I've heard the stories about Tim, but him and I must not have "gotten off on the wrong foot" as he was nothing but cordial to me through the build process. He's also since congratulated me when I let him know I've done particularly well shooting the USFT at a match. I shifted the field in which I work about 6 years ago, as I could see myself becoming bitter and frustrated being in the customer service area of my profession more than I am now. I can see how a couple decades of dealing with the public can make a guy be a little grumpy. I try to make it a point to not be one of THOSE customers though, when I find myself being on the customer side of things, and apparently Tim realized that and treated me accordingly. 

Arzrover and I were talking about the USFT late one night at the AZ state match a few weeks ago, and of course you came up. I was asking what details he knew about the high power USFT you competed with up in Oregon. I'd love to hear more about that particular gun (shot counts, how you got the power up, etc). 

Great insight into the development and history of the USFT. Very much appreciate it, and would love to hear any more that you're willing to share.