6.5 creedmoor

[doctorjj]

Its all in the BC of the bullets from my reading. I was on a mission to build one, when I realized there was a .243WSSM sitting in the safe. Doesn't make much sense to build a gun that isn't any better than one already has in the lighter bullets.

Both the Grendel and the Creedmoor fire heavier bullets than the 243 WSSM.

 

[dennishoddy]

Both the Grendel and the Creedmoor fire heavier bullets than the 243 WSSM.

Yes they do. The .243 100 grain will take everything I shoot until I go to the Rocky's for big game that needs a little more punch.

If I use Barnes TTSX the 100 grain will perform just about as well as some of the older lead core hunting bullets in bigger calibers/heavier weights.

That being said, I use the TTSX reloads in an .06 for elk at long ranges. I know its an old school caliber, but it sure works as well as the new whiz bangs within the limits of its range.

 

[henschman]

I have a LR-308 upper and complete lower laying around... the plan is to slap a JP 6.5 Creedmoor barrel and high pressure bolt on it. What I haven't decided is if I want to build my bolt gun first.

 

[dubs chops]

I have built one. PM me if you would like to talk specifics. There are some pressure issues with that round and the AR style bolt face you have to overcome.

BW

 

[doctorjj]

I have built one. PM me if you would like to talk specifics. There are some pressure issues with that round and the AR style bolt face you have to overcome.

BW

The design of the AR gas system should be able to be tuned with the gas port size/adjustable gas block and/or buffer weight to mitigate any issues with the bolt face or bolt lugs.

 

[dubs chops]

The design of the AR gas system should be able to be tuned with the gas port size/adjustable gas block and/or buffer weight to mitigate any issues with the bolt face or bolt lugs.

Unfortunately it does not on the standard AR bolt due to the floating firing pin. I have a fully adjustable gas block and the pressure is happening on the face before the spring/buffer ever come into play. I had to work through this over about a month period and there is no fix by simply tuning the gas system.

BW

 

[doctorjj]

Unfortunately it does not on the standard AR bolt due to the floating firing pin. I have a fully adjustable gas block and the pressure is happening on the face before the spring/buffer ever come into play. I had to work through this over about a month period and there is no fix by simply tuning the gas system.

BW

Explain further please?? The timing of the impulse, if appropriate, with the gas piston in the BCG, should unlock the pressure on the bolt face.

 

[dubs chops]

Its not in the timing of the impulse as far as I can tell,
Gas all the way off cratering or pierced primer.
Gas all the way open cratering or pierced primer.

the diameter of the firing pin hole in conjunction with the floating pin does not play well with the initial pressure of the round.

 

[doctorjj]

Its not in the timing of the impulse as far as I can tell,
Gas all the way off cratering or pierced primer.
Gas all the way open cratering or pierced primer.

the diameter of the firing pin hole in conjunction with the floating pin does not play well with the initial pressure of the round.

Reloads or factory ammo? 6.5 Creedmoor has the same operating pressure (and parent case) as the 308. No one has those problems with a 308. Has the headspace been checked?

 

[dubs chops]

factory ammo. reloads had some cratering but never pierced a primer.

I can't find a creedmoor pressure curve graph but I am thinking it may be steeper. Causing the problem before the bolt has ever had a chance to release.

I am not the only one that has experienced this. There are a lot of threads of people buying factory JP rifles and even GAP's having the exact same problem.