pokey

I should mention there is a free float tube that may hide any markings.

I now understand Go - NoGo - and Field gages (after a lot of reading) Now I see there are Nato head space gages as well. The Armalite, on there site looking at new barrels have a 7.65 X 51 / .308 chamber, which I think means it's a Nato chambers.

The rifle was a stripped receiver build by someone else. There are no visible markings on the barrel. Everything appears to be Armalite.

What ever chamber a Armalite has. The NoGo gage is a Clymer 308 WIN 1.634.

I've seen where on ar15's they will also use a field gage, I assume is larger. I don't know when this would be appropriate.

I've read that head space in an ar10 is larger than that of a bolt action rifle, is this true? Would it be typical for a ar10 to close on a NoGo, be it barely (using the force of one finger). Would anyone happen to have the bolt dimensions between the ar10 and the dpms pattern bolts. Just the bolts, not the carriers. Also, is it typical for the gas rings to be weak enough that while holding the bolt carrier bolt up, the bolt won't stay up (the weight of the bolt only, not the carrier). In ar15's I know you can hold the bolt facing down and the carrier won't drop. Thank you POKEY

Out of the bolt carrier how do you tell the difference between a ar10 and a lr 308 bolt. How would you know it a previous owner installed the correct bolt in the carrier.

It would be nice if we could talk companies into building a generic 308 (ar15 mil spec for example) type pattern, or at least more interchangeable . Armalite made a baby step with the A model. The proprietary designs hurt sales big time. It's the number one reason everybody I know don't buy one. For now, maybe a labeling system for what rifles the parts fit. Say something A for armalite, D for dpms and such. Maybe presenting a more constructive ,problem solving direction would help. Yes, trying to figure out what fits what drives me nuts. We should try to encourage vendors to label their parts compatibility . I know some people are going to be hard to work with.

thanks. You guys are great.

Thanks for the replies. I suppose the higher than normal scope height as compared to say a 700 Remington may have played a role also. All rounds were the same over all length, trimmed to the same length, and powder trickled. The drop difference was about 2" . No chronograph readings, hey I'm a poor boy! Looks like I may buy one soon. The .308 is a 20" barrel with 11.25/1. The .223 Is a 16" barrel with 9/1 .

Yes, all testing was done with the same bullet weight. No, it wasn't cold bore. The .308 was a 20" with a 11.25 twist. The .223 was a 16" barrel with 1/9 twist. The tests were done at .2 grains at a time. 100 yard distance. The .223 was on a lead sled. .308 on a regular rest/sand bag, because I thought the lead sled may be affecting something.

No. The rifles were sighted in with 150grand 55gr. The ladders were run with 168gr, and 69gr. Like I said, they were .308 and .223. It just seems really backwards.

One rifle sighted in at 200 yards, and the other at 100 yards. Both tests were done at 100 yards. No they weren't sighted in with these bullets. The rifle sighted in at 200 was a .308, and the other rifle sighted in at 100 was a .223.

Why if you were shooting ladders, would the bullets impact lower with higher powder charge? Before you ask, it was the same case, powder, primer, and bullet. The only thing that changed was the amount of powder. As the powder charge increased the point of impact lowered. This was true with two different rifles with four different tests. I expected the opposite. I know everything was correct, didn't load the rounds in reverse order (the heavier loaded rounds were on the bottom of the mag), or anything like that. Positive of the order they were fired in. What gives? Pokey.

How about a leatherwood camputer scope. Once you know your ballistics, loosen a couple of rings and set (about 2 min). Then you range out to 200-1000 yards using the reticle with bracketing and turning a ring, done. No need to even take your eye out of the scope. Set it once and forget it. If you know your bullet velocity, weight, and coefficient . Plug it into something like the hornady ballistics site. your scope instructions tell you what number to set it at. I've made this sound complicated and it isn't. This is the same style scope that Vietnam snipers used and is good for hunting or sniper duties. One bad side is out to 200 yards you will be at two power, and at 300 yards three power, and so on to 10 power at 1000 yards. If you like a lot of magnification at 100 yards, it's probably not for you. It does surprisingly well at 100-200 yards, don't expect to see holes in paper though.