Chamber is too tight to seat pellets – What do I do?!

[JungleShooter]

I changed the barrel on my PP700 – and now after shooting about 100 pellets my thumbs are hurting like crazy!

The chamber on this barrel is way too tight.


What can I do about that? What options are there?





Note: With a lot of force I can get the pellet to seat in the chamber, and some pellets with softer lead (JSB) seat easier that those with harder lead (H&N, Crosman).
And I might be fine growing elephant skin on my thumbs.


BUT....
I noticed extreme fliers on my otherwise rather tight groups. 
And I remembered reading Mile's (BallisticBoy's) article on how the tiniest imperfections on the pellet will lead to large POI changes. 

➔ Soooo, I think elephant skin isn't going to be enough – instead of an organic solution I'll need ananorganic one (as in "metal"....)  




Matthias

 

[nervoustrig]

If you’re using hand tools, it’s going to take some time with wet/dry sandpaper to remove enough material to form a subtly tapered leade. Cratex points—rubberized abrasive bits—or the generic variety in a hand drill will make shorter work of it without being too aggressive.

 

[jwrabbit123]

HI I know on my slug barrels I or they ream the breech to cycle slugs easily , but I never had this with a pellet , maybe ream it out first 1/4 inch , I know if a pellet is that hard to seat fliers may be bending the skirt while trying to load it sounds like you have tested a few kinds , so if the head is binding you need to ream it out

what caliber is it ?

 

[Bocephus]

Try a pellet sizer.

 

[JungleShooter]

Cratex, that looks interesting (and doable!).



$7.15 for the rubber abrasive cone

$9.10 for the mandrel



Wait, the barrel cost less than that....  



But then I'll have a tool for the next gun....



They offer four grades of grit:

coarse | medium | fine | extra fine

What would you recommend?







It's a .22cal. I had one pellet came back out after I tried to seat it. And when I looked at the head — not good...  

For critters at 10 yards not a problem, but for longer ranges this makes a difference.

Just look at this target card, 5 shots at 25y....



Matthias

 

[mtnGhost]

The correct way to fix this problem is cutting a new chamber using a proper throat reamer. The operative word is concentricity. Reaming it improperly will only make things worse. I'm not saying that it can't be done without a good piloted barrel reamer, I read some accounts by guys like @motorhead that have made reamers using modified drill bits - but I wouldn't want to practice on the barrel that you plan to use. 

Whatever you wind up doing, my advice is:

1. Be patient 
2. Go slow - only remove a couple thou of material at a time
3. Clean after each pass
4. Test your progress after each pass
5. Maintain patience!
   [/LIST=1]
   
   Good luck!

 

[nervoustrig]

That's why I said "or the generic variety"
https://www.ebay.com/itm/10x-Tapered-Rubber-Polishing-Head-Abrasive-Grinding-Burr-Bits-Mounted-Point-5mm/222543186998

Available in many sizes...just get one slightly larger than your caliber and use a stone or coarse sandpaper to reduce its diameter to what you need.

 

[DemWitt]

I’m a fan of craytex and the like abrasives. I would use a medium grit. While mtnghost’s answer is the best, like nervoustrigger, I would give the craytex a try. Easy does it!

 

[nervoustrig]

For this type of job, the abrasive points will do the trick but if you have access to a lathe, get a 5.6mm reamer (for .22 cal / 5.5mm).

https://www.aliexpress.com/item/32535264032.html

Basically all the flutes will be removing is the rifling. It's a very small amount of material but you still want to feed very slowly and clear the chips often. And although a reamer leaves a cleaner finish than a common drill bit, you still want to spend a little time cleaning up the machining marks with one of the rubberized abrasive bits (or wet/dry paper) and break the sharp leading edge of the rifling so pellets can ease into the rifling rather than getting cut.

 

[Vetmx]

Jungleshooter, if you are going to keep messing with the Chinese stuff, you need to make friends with a guy who has a lathe. SPA made me very creative on a lathe. 

 

[boscoebrea]

 O yea,concentricity,a word not used much and practiced even less...

 

[marflow]

yes those bits from China work very well, i bought 3 sizes just to have, you can just spin with your fingers get some material removed 

all Chaser barrels need a little work 

if anything thing else they are nice to have when you need just the right tool 

 

[HeyU]

I had a tight breach on my 22 underlever. I used crocus cloth wrapped around a hex wrench and worked it till I got a good fit. Crocus cloth is finer than emery cloth and pretty durable. I felt it was a safe approach. And it did'nt take to long.

 

[leadfoot]

Try some smaller head sized pellets. H&N have a Bunch of sizes available from most suppliers. They may work very well.

 

[BlackICE]

I would using a boring bar compared to using a reamer?

 

[leadfoot]

The reason I suggested the smaller head sized pellets is that if you have a very tight chamber, you may also have a slightly undersized bore. Just to have the pellet fit the chamber, then get squeezed in the bore, may not be best for accuracy. 

 

[boscoebrea]

Great idea to try smaller head pellets first...they may work and be plenty accurate..I had a hard time "feeding" a springer of mine,I just radius the opening and that worked out fine and did have to worry about concentriicty...one other thing that may be playing a role is not enough depth in your chamber...try shorter pellets to...if all that does not work and you also smoothed out your chamber...good luck and remember "ain't no big thing to get down and boss your barrel around instead of the other way around.

 

[JungleShooter]

Wow, thank you for all the tips and ideas!  



Frank/Vetmx, I'll take your advice and will be looking for a lathe-friendship...! Maybe an ad in the Sell&Trade section: "I teach you how to do good workshops — in exchange for lathe work."  



Considering that the barrel only cost $15 — I might be better off buying a couple more tickets for the Chinese barrel lottery....!  



However, I will try some of the less expensive tips from nervoustrigger's Barrel Accurizing Guide, here:

https://www.gatewaytoairguns.org/GTA/index.php?topic=130555



Thank you all!  

Matthias

 

[Vetmx]

If you lived closer, I would hook you up.

 

[preventec47]

I had the same problem and what I did was try different brand and model of pellets and I found some are smaller than others and fit easily into my chamber.

I happen to shoot .177 but I bet there are microscopic differences in the sizes of various 22 cal pellets.

FYI, I happen to shoot very heavy 177 pellets and the two heavy pellets that I found to be on the smaller size and fit easily into my RWS 48 Springer are

the 16.2gr Exact Beast Diablo and the H&N Sport "Sniper Magnum of 15gr each. Yes I am sure .177 cal.