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Posted: 2/23/2011 7:58:40 AM EDT
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I'm currently considering getting in on a group buy of 6.5 LW barrels. They come with a headspaced AA bolt, which is slightly different than a 7.62x39 bolt. I can also purchase one of ITS's 7.62x39 Superbolts (supposed to be much stronger) and have them headspace the barrel to that bolt instead. I'm trying to decide what the best option here is. It would cost be about $50 more to purchase my own Superbolt and send it to them for headspacing.
How much stronger is the ITS bolt than the AA bolt? How much stronger is the AA bolt than a standard 7.62x39 bolt? (if I get the ITS and for some reason they are unavailable in the future, I would have to replace it with a 7.62x39 bolt for it to headspace properly) Is it worth the extra money to get the ITS or am I overthinking this and sticking with the AA bolt is the best option? |
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I have had two AA 6.5 Grendels for five years. They bolts are rock solid and I never had an issue with them. I would save the $50 and buy two extra boxes of ammo for them.
The most accurate load is the AA loaded 123 Lapua Scenars. The cheapest load is the new Horndady 123 gr AMAX at around $20 a box of 20. For home defense, I use the 129 gr SST that AA loads as they have serious penetration and expanstion. Kind of a hybrid of a HP and AMAX but meant for penetration while the AMAX opens up too fast for home defense. |
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As long as you don't run the Grendel to "hot", you should be OK w/ the AA bolt.
Of course you can bet both, if money is not a Issue...that 9310 alloy is about the strongest you can get and it can handle quite a bit more pressure vs. the C82 or C83 series alloys... |
| The ITS bolt seems like it would be a bit more versatile as it headspaces the same as a 7.62x39 bolt, but LW has the AA type bolts, so maybe just score an extra one as backup. They are finishing up a run of 18" SPR barrels for me right now and they are using the AA-type bolt because they have them. |
| I've got an LW bbl in 6.5CSS that was chambered with a stock 7.62x39 bolt face. I also have an AA bbl and bolt combo. I ran a DPMS standard 7.62x39 bolt in my LW bbl for many rounds, most pretty warm and its never failed. I've since then bought an LMT enhanced bolt for it. The only real advantage to the 7.62x39 is the availability of an extra bolt. The only difference between the AA spec vs the standard 7.62x39 is the AA bolt face is recessed 0.011" deeper than the 7.62x39. |
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If you stay with normal ammo you will never have a problem. Some of the older AA load data seems to be on the warm side if you follow my drift.
Hornady loads the ammo to safe and industry respected velocities. Its a very efficient cartridge, you don't have to overload it. There is some question concerning correct headspace but it is being corrected as we speak. I think I heard 1.217 as the corrected number but I may be wrong. In any event, saner heads are on the problem and it will get fixed. |
| As long as you use the bolt it was chambered with, the headspace will remain the same regardless of which bolt is used. The headspace on the standard face 7.62x39 bolt is the same headspace as one chambered with an AA spec'd bolt. Both types would be 1.217" if that's the correct spec. |
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Quoted:
As long as you use the bolt it was chambered with, the headspace will remain the same regardless of which bolt is used. The headspace on the standard face 7.62x39 bolt is the same headspace as one chambered with an AA spec'd bolt. Both types would be 1.217" if that's the correct spec. The OP wanted to know if it was worth it to switch bolt types. It would involve cutting the chamber. 011" deeper, and the OP would be using a stronger bolt... Imho you'll be fine with the AA bolt. I've run quite a few warm 140gr loads thru mine without issue. |
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Quoted:
Quoted:
As long as you use the bolt it was chambered with, the headspace will remain the same regardless of which bolt is used. The headspace on the standard face 7.62x39 bolt is the same headspace as one chambered with an AA spec'd bolt. Both types would be 1.217" if that's the correct spec. The OP wanted to know if it was worth it to switch bolt types. It would involve cutting the chamber. 011" deeper, and the OP would be using a stronger bolt... Imho you'll be fine with the AA bolt. I've run quite a few warm 140gr loads thru mine without issue. Actually it wouldn't involve cutting the chamber deeper because the chambers aren't cut yet. 
and yes, either would be just fine. |
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Quoted:
I have had two AA 6.5 Grendels for five years. They bolts are rock solid and I never had an issue with them. I would save the $50 and buy two extra boxes of ammo for them. The most accurate load is the AA loaded 123 Lapua Scenars. The cheapest load is the new Horndady 123 gr AMAX at around $20 a box of 20. For home defense, I use the 129 gr SST that AA loads as they have serious penetration and expanstion. Kind of a hybrid of a HP and AMAX but meant for penetration while the AMAX opens up too fast for home defense. Truth, this person speaks it. |
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Quoted:
I have had two AA 6.5 Grendels for five years. They bolts are rock solid and I never had an issue with them. I would save the $50 and buy two extra boxes of ammo for them. The most accurate load is the AA loaded 123 Lapua Scenars. The cheapest load is the new Horndady 123 gr AMAX at around $20 a box of 20. For home defense, I use the 129 gr SST that AA loads as they have serious penetration and expanstion. Kind of a hybrid of a HP and AMAX but meant for penetration while the AMAX opens up too fast for home defense. I just finished my 6.5 build and have been researching it for the past three years. Everything I have read from experienced shooters confirms the above. |
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I have had 3 Grendel bolts break. The problem has been traced back to an out of alignment facing where the barrel extension goes into the upper receiver. Because most uppers are not perfectly square, when you torque down the barrel nut, there is a tiny bit more pressure, or lack of pressure on areas that are high or low. I contacted ARprecision, and they faced off the upper receiver to make it perfectly square and aligned with the bolt recess in the upper. Since then, I have had no problems with bolt breakage.
The same issue happened on an aftermarked rifle assembled with some Alexander Arms parts. The rifle was NOT built by Alexander arms however. After I returned the rifle to Alexander Arms, they rebuilt the rifle (wonderful job too) for a shockingly reasonable price. Since Alexander Arms assembled the rifle, I have not had a single problem with the rifle. Two of the bolts that broke were supposed to be super bolts. The bolt that broke on the rifle made out of Alexander Arms parts (but was NOT an Alexander Arms rifle) was of unknown origin. Once AA rebuilt the rifle, it shoots fabulous, and works 100%. For what it is worth, the rifle shoots well enough that it won a precision rifle match against 70 other rifles including ones from some of the top custom makers, and manufacturers. The problems usually aren't with the bolt, the problems are an out of perfect alignment barrel recess on the upper receiver. |
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