6.5 Grendel Match reamer

[AlaF]

Do any of you have any experience with PacNor's 6.5 Grendel Match chamber and how (if at all) it differs from a SAAMI chamber? Thank you.

[JASmith]

Best thing to do is call them directly.

Ask if they have a reamer cut to SAAMI specs. If so, go with it.

If not, and you are happy with the description and drawing if they send a copy, then go for it. Just remember that you will have to work a little harder to get the best accuracy from the barrel. Some claim that the "best accuracy" from a "match chamber" is better than one gets from a SAAMI chamber.

The difference in accuracy potential, if any, is so slight that one rarely sees better performance than with the SAAMI spec chamber. The reason is that the 0.5 degree taper in the SAAMI throat (where the freebore normally is) gets excellent alignment and tolerates larger jumps than the typical 1.5 degree "target throat and conventional freebore do.

[bwaites]

I would consider a match chamber only in a bolt gun.

[cory]

First let me say I don't know the specifications of the pac nor match chamber. I've always been curios, but I've never had a reason to do the research. If you find out please post it here.

Second, I do share Bwaite's opinion here.

I greatly respect the opinion of JASmith especially on the issues of chambers. However, I'm not in full agreement with him here. Whether a "match" chamber and a SAAMI spec chamber is right for you is not a simple answer. You first need to determine how you plan to use this build.

Do you intend to stay within the SAAMI pressure limit of 52ksi or do you plan to exceed that limit to 55ksi, 60ksi, or 60ksi+? Know that if you exceed 52ksi you will be sacrificing brass life.

If you intend to stay within the 52ksi limit then stick with the proven SAAMI chamber with the compound throat and .300 neck.

If you intend to exceed 52ksi then I think the .295" neck begins to makes since in order to save some brass life as you give up nothing in a bolt action.

Once you start shooting in the 60ksi pressure range the compound throat becomes useless and you'll likely, eventually, degrade that compound angle into a single angle.

What bullets will you be shooting? Pushing the pressure limits with 123gr and below will offer little benefit if any. The heavier bullets are where you'll start to see benefit in pushing the pressures.

I'm assuming that you'll be reloading. If not, go with the SAAMI chamber.

[AlaF]

The rifle will be a bolt action built on a Borden Alpine single shot action and I would be reloading and would like to try up to 140gr bullets, but expect mostly to use 123-129gr bullets. Not really planning to push things too much beyond 52ksi. Accuracy is my primary goal. PacNor sent me a copy of the reamer print in jpeg format. I'll have to see if I can figure out how to load it here.

[ricsmall]

Pac nor chamber has a .295 neck and parallel throat.

Richard

[JASmith]

I like Pac-Nor, they did an excellent job on my 20 Grendel. It has a parallel freebore and the reamer was cut to my specifactions by Manson Reamers.

That said, however, I eould press them for a SAAMI-Compliant chamber.

My 20 Grendel can turn in .5 moa or better accuracy without a lot of tuning but if the seating depth is more than .005" off optimum grows to more than an moa with at least one of the bullets I am working with.

My TC Encore single shot with 6.5 Grendel SAAMI chamber has turned in a number of sub .5 moa groups with no effort put onto tuning for accuracy.

[am4966]

Josh Kunz @ Patriot Valley Arms will make you a Grendel barrel. He uses JGSprecision reamer(saami) for Grendel's. I'm going to have him make me a Hawk Hill barrel when I'm ready. He does top notch work. He's not cheap, plus he's a LR shooter too.

I'm not a 100% but he probably could make you a match chamber if you wanted one. If your interested in contacting him let me know and I'll pm you his email

[BjornF16]

I received this from PacNor a while back...personally, if I had it to do over again, I would send them a SAAMI reamer to chamber my barrel

[SDguy]

Keep in mind you are asking a generally biased crowd as historicaly this has been AR

Keep in mind you are asking a generally biased crowd as historicaly this has been AR round. Thus folks seem to gravitate twards preferred conditions for the AR platform.

you could not go to far wrong w a true Sami Grendel chamber. Although in a bolt gun i d prefer the idea of a tighter neck personally.

Sorry to say I Can not speak directly to a Pacnor Match chamber. I do have a CZ 527 with a Lothar Walther barrel that I am quite happy with. Not sure about all the specifics of the Lothar Walther Chamber @ throat. Does have a .005 tighter neck (.295).

Does well for me!

[ricsmall]

If you're building on that action I personally would have a reamer cut with matching throat to the bullet I intended to use the most. Load up dummy rounds with the 140 gr and 123 or 130 gr of your choice and make a compromise to fit both or fit to the load you would be set on using. If hunting I would go with .295 neck. If strictly paper punching I would go with tightest no turn neck I could get. No turn because I don't like having that extra step.

Having said that, my personal bolt Grendel I built is saami chambered so I can start my son out with 100 grain pills and still move up to the 130 ar hybrid at some point. I'll never shoot 140's as I have a 260 AI for that. Hope this helps your decision.
I'm not disputing these other opinions, but if you are gonna be set on using one or two pills you don't need the versatility of the compound throat, and if you're not gonna have the compound throat you need to go with tighter neck to help with alignment.

Richard