New 10" barrel, bullet stability problems

[rsilvers]

Stainless makes sense for one-off barrels. If we did not do nitriding, we would be doing stainless - for the bolt guns at least.

[sha-ul]

Originally Posted by rsilvers

Stainless makes sense for one-off barrels. If we did not do nitriding, we would be doing stainless - for the bolt guns at least.

that whole nitriding process sounds very interesting... ans I've heard you can do stainless as well

[rsilvers]

You can do 416 stainless, but the result is much less corrosion resistant than if you do carbon steel.

This is why S&W was getting rust when they Melonited their M&P stainless slides. Glock uses carbon steel and - never rust. So nitriding stainless is not only more expensive, but a worse result.

The ultimate barrel is carbon steel with nitride.

[snipecatcher]

While we are on the subject: CAN a nitrided barrel be machined, or is there some type of preparation to remove the nitriding before machine work? As an example, say I wanted to have a different muzzle thread on a nitrided barrel. What's the process?
-Dan

[rsilvers]

You can machine it with carbide tooling.

We have taken our 9 inch nitrided barrels and chopped some to 7 inches.

[Mike Bell]

Robert,

I work at MGW Precision in Augusta GA. We make parts for other companies besides our self, and some of them have stop having me blue their parts becuase they went to the Melonite finish. Where can I find more info about this process?

We are an O.E.M. supplier but we have our own line of gunsmithing tools and some pistols parts (1911) that we might try out.

My boss is into cars so he is really doesnt care much for the gun stuff......We tried like heck to get him into the AR rifle market and you know what he said....."AR's are just a fad....it wont last." little does he know!!!!

[HotLead]

Mike,

check out the H.E.F. site; here is a link:

http://www.hefusa.net/melonite-QPQ-arcor.htm

Here is the link to the Accurate Shooter site that has the H.E.F. pricing and point to contact info:

http://www.accurateshooter.net/Adver...eorderform.pdf

Now that I have my can, I plan to have this done to my TP555 300BLK barrel.

[snipecatcher]

Got the new stainless barrel from Douglas. Other than being stainless, the specs are the same, it's a 10" with 1 in 7 twist. The results are looking better, but I'm still not sure. I have some targets from today:












The 240's appear to be ok at 10 yards, but the holes still aren't perfect. I don't feel comfortable shooting them through a suppressor. At 100 yards, they are not stable either. Some make round holes, some oblong. They are marginally stable. If I up the charge and get them going 100 fps faster (into supersonic territory) they get better.

The 208's make nice round holes at 10 yards and at 100. They are also fairly accurate.

The 220 Pro-hunters shot the best group of the day at 1.15", but appear to be unstable. This is strange considering they are quite a bit shorter than the 208's.

[Retooferab]

What powders are you using? I have had good luck with N110, AA9, and 1680. My most developed loads are 8.6gns N110 and 8.2gns AA9 I have been using 2.09 oal keep in mind that for about every .10 oal you can change about a .1 gn..... ........I have been using 220SMK bullets


What I am saying is if your load is 8.7gns using say 2.19 oal if you change the oal to 2.09 you should reduce your load .1gn to keep the same velocity.
At least this is how it is working in my 10.5" ar.

[snipecatcher]

I've used 3 different powders, at many charge weights, trying many combinations of bullet/seating depth. So far, the only bullet that appears to work in this barrel is the 208 Amax. I took some with me this weekend and shot them at 150 yards, and they were stable, BUT, my load was a consistent 1120 fps. I mis-judged the charge weight a bit. I'm going to load up some more at 1050 fps and see how they shoot. It sucks being stuck with one bullet, which is perpetually out of stock, but if they work, I'll make the 200 or so that I have last.
-Dan