[stdriver]

Image is proof that a 9.5 twist barrel is not as bad as most of you say.

Bore lapped using Tubb's bore lapping bullets

Slightly flattened primers with no other pressure signs

every shot chronographed and documented

 

[constructor]

I don't think they or we say they aren't accurate, I believe we say they will show pressure like slightly flattened primers earlier

 

[Cold]

Good shooting sir!

 

[SgtScrap]

What powder, and how many grains did you use. Imr4198 or H4198. It is kind of blurry on my computer. Nice group by the way. I have some 130 gr Nos that I am planning to reload.

 

[stdriver]

What powder, and how many grains did you use. Imr4198 or H4198. It is kind of blurry on my computer. Nice group by the way. I have some 130 gr Nos that I am planning to reload.

I used 23 grains of H4198 and the load was slightly compressed. The picture is blurry from trying to take a picture with a digital camera and no tripod.

Stdriver

 

[Equalizer_2]

I used 23 grains of H4198 and the load was slightly compressed. The picture is blurry from trying to take a picture with a digital camera and no tripod.

Stdriver

Check to see if your camera has different settings available. It looks more like it was out of focus due to you being too close to the target.

I have a camera that has a selector that shows a flower that is the setting to use when taking close up shots. It has a person with a silhouette of a person and a couple of lines drawn to the side to indicate shaking so it reduces blur from action and movement.

Some of these cameras can be tough to figure out.

 

[Test_User]

Very good shooting and nice load!!!!!! Sweet!!

As Paulo said the issue with the 9.5:1 is pressure and thus vel. Once enough to stabilize a bullet twist has very little to do with accuracy. You are using them in the best way with longer bullets that can are better matched with the faster twist. and the longer barrel length almost works well with that.

What make barrel is it? SAMMI or SPCII chamber?

That is certainly a great accuracy load and not that bad of a velocity for such a fast powder with a heavy longer bullet like that. It looks like 3shot group correct? If so have you do any high round count groups with it? 5? 10? I know its not a cheap bullet so Io understand it not.

If you care to tinker you and want to get some more vel you might want to try a slower powder. 4198 is very fast and normally used for 90 gr bullets and under especially in longer barrels. It builds pressure very fast when used behind heavy longer nearing surface bullets limiting vel. Given you have a 20" and are using a heavy longer bullet a powder like rel10x aa2520 benchmark might be worth a look but I would certainly keep that load in my books..

What COAL did you laod them to?

 

[stdriver]

Very good shooting and nice load!!!!!! Sweet!!

As Paulo said the issue with the 9.5:1 is pressure and thus vel. Once enough to stabilize a bullet twist has very little to do with accuracy. You are using them in the best way with longer bullets that can are better matched with the faster twist. and the longer barrel length almost works well with that.

What make barrel is it? SAMMI or SPCII chamber?

That is certainly a great accuracy load and not that bad of a velocity for such a fast powder with a heavy longer bullet like that. It looks like 3shot group correct? If so have you do any high round count groups with it? 5? 10? I know its not a cheap bullet so Io understand it not.

If you care to tinker you and want to get some more vel you might want to try a slower powder. 4198 is very fast and normally used for 90 gr bullets and under especially in longer barrels. It builds pressure very fast when used behind heavy longer nearing surface bullets limiting vel. Given you have a 20" and are using a heavy longer bullet a powder like rel10x aa2520 benchmark might be worth a look but I would certainly keep that load in my books..

What COAL did you laod them to?

Hi Tim: Right now my barrel is a SAMMI chamber from Model1Sales, However I'm on the list to get it reamed to SPCII specs.

I have tried other powders like IMR4227 and H322 but run out of case volume and really compressing the powder especially with
H322. I would suspect that slower burning powders would require even more space to get the velocity up the 2400 fps or better using 130 grain bullets, and yes I could use a lighter bullet, but IMO that would cause accuracy to open up due to the twist and I have used them to prove my point.

The COAL is the max at 2.260 for my AR due to mag limitations.

Thanks stdriver

 

[Test_User]

Yes that is what I was wondering about. Sometime from a capacity issue a faster than normally used powder ends up working better. That would likely change if you get a PRI or CP mag and stretch it out to 2.28-2.29

 

[David]

Hi Tim: Right now my barrel is a SAMMI chamber from Model1Sales, However I'm on the list to get it reamed to SPCII specs.

I have tried other powders like IMR4227 and H322 but run out of case volume and really compressing the powder especially with
H322. I would suspect that slower burning powders would require even more space to get the velocity up the 2400 fps or better using 130 grain bullets, and yes I could use a lighter bullet, but IMO that would cause accuracy to open up due to the twist and I have used them to prove my point.

The COAL is the max at 2.260 for my AR due to mag limitations.

Thanks stdriver

I'm very interested in your results with the SPCII chamber. I also have the Model1Sales upper (vintage 2004) and, while I have an Xtreme on pre-order with Titan, am fence-sitting on keeping the M1S upper or selling it once I get the Xtreme. Even reaming the chamber out to SPCII probably wouldn't let me safely shoot the same loads (SSA Combat or similar handloads) in my old upper, so I'd have to keep two sets of ammo on hand...not my idea of a "best practice."

 

[stdriver]

I'm very interested in your results with the SPCII chamber. I also have the Model1Sales upper (vintage 2004) and, while I have an Xtreme on pre-order with Titan, am fence-sitting on keeping the M1S upper or selling it once I get the Xtreme. Even reaming the chamber out to SPCII probably wouldn't let me safely shoot the same loads (SSA Combat or similar handloads) in my old upper, so I'd have to keep two sets of ammo on hand...not my idea of a "best practice."

So am I, still waiting for that SPC II reamer to arrive so I can start expermenting with loads again, Also picked up some Hodgdon Benchmark and loaded 30 rounds with different bullets to get the velocity up with a slower burning powder.

Will keep everybody posted.

Stdriver

 

[stdriver]

After reaming the Barrel

Five shot group with 130 gr. Nolser Ballistic tips @ 100 yds.

100 degree day here in south Louisiana, Average velocity 2455 with 26.5 gr. of Reloder 10x

All five bullet holes can be covered with a nickel, actual measurement .770 top to bottom.

using once fired Remington brass with Federal primers, no ejector swipes, just some mild flating of primers.

stdriver

 

[paulosantos]

Thanks for the update. Great shooting.