I need BC of 31 grain .25 H&N Grizzlies

[JamesD.]

Rough estimate please. I have Piledrivers in .22 with BC of 0.08 but waiting to Get Rainstorm .22 factory spring I found specs for.

The .25 Grizzlies will be tested out of R5M Supermagnum & older 500cc .253” Sumatra.

 

[jwrabbit123]

they are .07 They did not group well in any my guns , I am looking forward to their new ammo they talked about they will release soon , In my R5 25super mag cal they grouped about 3 inches at 50 yards , post a group if it is good pls





LOU

 

[jwrabbit123]

For Sumatra try hunters supply 49 gr they made for this gun

 

[JamesD.]

@jw, I have an older .253” Sumatra & Dale D-rig of Varmint Knockers makes them special in 57 & 60 grain. The 60 grain even has a gas check.

I don’t know why but when shooting 50 grain .253 slugs my Sumatra lever action wants to open. Needs a J slot for a lever action, lol.

ive been told Grizzlies shoot really well from R5M. Mine will be here this week. I have no Grizzlies, only JSB 34.95 original & Rat Sniper 31.5 or .9 grain RBT slugs. I wanted to get several VK, Nielsen, more Rat Sniper. 

I wish Piledrivers came in .25 

What drag coefficient should I use for Grizzlies on Chairgun Pro?

 

[JamesD.]

Hey buddy, I could PM you, but for everyone else & I have an offer for 25 tins of 43 grain .25 Eun Jin’s which are very hard and will penetrate way better than any other Diabolo pellet. What’s rough BC? I’m deciding if I want to buy them all. 

Oh & I need head diameter of Grizzlies & Eun Jin to 0.000” because my Sumatra is .253 & R5M Supermagnum is .251 grooves, .246 lands. Tight little quarter bore when I ideally if shooting slugs only would have no choke, correct chamber cut for one slugs proper engagement & sized 0.0003” over for least deep fins yet enough bite to stabilize that sucker. Allegedly much less leading up if set correctly also.

 

[JungleShooter]

ChairGun has the BC for the .25 Eun Jins as follows:

● 43.00gr, pointed with rings: 0.032BC

● 35.00gr, flat-domed with rings: 0.029BC



Bob Sterne measured the BC, however he had only access to ChairGun 3, that uses the G1 drag function, so the values are probably a bit better (higher BC), than if we would calculate the BC using the GA drag function that ChairGun 4 came with.

His post is here: https://www.gatewaytoairguns.org/GTA/index.php?topic=29256.0

He shot the Eun Jin 42.4gr Pointed pellet with 56FPE, MV at 774, Velocity after 25y at target 711fps: 0.035BC



Happy shooting!

Matthias

 

[JamesD.]

Thanks guys. I’ll post group when I get some. I need some MKII’s also. I’ll try the 49’s in Sumatra.

The EDgun Supermagnum is doing great at 200 with Kings & 34.95’s, So is Sumatra. I have a .25 ST coming I’ll probably sell cheap as I want a .22 slug barrel for the Elite along with the 2 groove .22 for pellets. It may do well with certain slugs & JSB 25.43 .22’s.