510 AM test

[Fiftydriver]

Jerry,

I will take some better pics of her on the range soon. Hope to get her back out in a couple days if work permits.



This gives you an idea though. The rifle below it is my 224 AM which is basically a Sendero sized rifle!!

More to come soon when I get her out for her first long range test soon.

Kirby Allen(50)

[lovdasnow]

wow!!! speechless... [img]/ubbthreads/images/graemlins/grin.gif[/img]

[Fiftydriver]

I decided to clean the 510 AM yesterday as I was working in the shop. She had about 20 rounds through the bore ranging from 750 gr A-maxes at 2500 fps up to 835 gr Wildcats pushing 2800 fps.

Ran a butches bore shine soaked bronze brush down the bore for 5 strokes, resoaked and repeated another 5 strokes and then wiped out with a couple dry cotton patches.

Then soaked the bore with Tetras copper solvent for 15 minutes and when I pushed that out the barrel was spotless!!! I had to resoak with tetras and let it sit another 15 minutes just to make sure but it came out clear as it went in.

This may not sound all that impressive unless you are accustom to 50 BMGs and cleaning them. I am very impressed with the bore finish on this Lilja barrel, just as good as any smaller caliber Lilja I have used.



Here are a couple pairs of fireforming loads at 100 yards. I shot the one on the left and a friend from Canada shot the one on the right. This was the first two shots he had ever taken with a 50 cal. I think she will be a shooter!!

Kirby Allen(50)

[ QUOTE ]

This may not sound all that impressive unless you are accustom to 50 BMGs and cleaning them. I am very impressed with the bore finish on this Lilja barrel, just as good as any smaller caliber Lilja I have used.
Kirby Allen(50)

[/ QUOTE ]

Wow, that's amazing. I have four custom 50 BMGs - my borescope shows the barrels very smooth. I thought copper removal just went with 50's (I even became an ammoniacal expert in the process of optimizing the cleaning).

Maybe your just not pushing it hard enough [img]/ubbthreads/images/graemlins/smile.gif[/img]

[edge]

I was curious to know if you have good accuracy shooting sabots?

If you have problems with accuracy, I have found that sabot/bullet separation is normally the problem with rigid sabots ( unlike those used for most muzzleloading rifles ).



If you have access to a lathe, I suggest a groove machined into the sabot that will ensure that the petals shear off.

On the sabots in the picture the groove is 0.059 wide, 0.020 larger in diameter than the bullets base, and 0.020 beneath the bullet. This last feature is very important. I used to put the groove right at the base of the bullet, but when firing the bullet would actually extrude into this unsupported area.

edge.

[ QUOTE ]
I was curious to know if you have good accuracy shooting sabots?

If you have problems with accuracy, I have found that sabot/bullet separation is normally the problem with rigid sabots ( unlike those used for most muzzleloading rifles ).

edge.

[/ QUOTE ]

My goal is 2.5 MOA - which is pretty accurate for a SABOT. Click HERE to see my SABOT's (pressed to different levels - just for a pic - I only shoot them fully pressed). I don't think separation is a problem.

[image]http://groups.msn.com/50bmg/sabot.msnw?action=ShowPhoto&PhotoID=93[/image]
150 gr .308 API (pulled). I'll be shooting 150 SMK and 155gr Scenars too.

[edge]

I agree, if your goal is 2.5 moa than you are likely to be able to achieve that with some care...and some occasional fliers.

Those in my picture above are 0.458 sabots and 150grain SST's.
I also am only in the 3k fps area and you are likely 1k or more above that. I do also shoot 150 8mm Game King bullets from my 0.505 barrel at well under 1 moa.

I originally shot sabots based on those in your picture, actually those from Beastwerks, but accuracy was not what I wanted for deer hunting. I began searching the web for sabot designs and found that much of the dispersion in military rounds was either from a lack of support in the barrel ( balloting), which should not be an issue with your sabots, or inconsistent sabot separation including various amounts of contact with the sabot during separation.

Out of curiosity, do you get 50 cal holes or 30 cal holes in your target? IF you get 30 caliber holes, I might suggest that you epoxy or super glue the bullet into a few sabots to ensure that they do NOT separate! If these bullets are substantially more accurate then sabot separation IS an issue!

When testing sabot designs I do not slit the sabot petals for the first few shots to make sure that they are leaving the rifle in a stabilized manner. Only after I am sure that I have nice clean 50 cal round holes do I make the sabots of the discarding type.

edge.