Gunsmithing .510 whisper in progress now

[FTF]

Re: .510 whisper gunsmith

I have everything now, EXCEPT dies, they will still be awhile longer from Hornady. Never could get a response from the CH4D folks so no idea if they are still interested in making the dies or not. Patience is definitely a major requirement for ALL the Sub Sonic endeavors!

Thanks,
Emory Jones

 

[biffj]

Re: .510 whisper gunsmith

Well the bad news is that the factory mags won't work as is for more than one round. They use the shoulder of the round to keep the bullet from hitting the mag under recoil. The idea is to keep from screwing up the ballistics and I'm sure its a great idea for the heavy recoiling rounds. That means the mag pinches down right in front of where the 338 shoulder sits and this is where the huge .50 cal bullet needs room. The good news is that the magwell has plenty of room so modifying or making a special mag would work. I can see a couple ways to fix the existing mag but it requires either forming or welding and cutting.

I threaded the barrel for this particular rifle .875-24 though all the standard barrels for the rifle are .750-24. I figured the larger diameter would be good for the huge hole in barrel as well as keeping the aluminum suppressor I'm building for it from being used on the high pressure rounds....308, 300 win mag and 338. I'd hate to see the aluminum can blasted to shreds and I don't think I really need a super heavy steel can for the 510. I'll build a steel can for the other cals and they will all be able to use the same can.

I just got a set of 300W dies from CH4D that were on backorder. I've not had any problems getting in touch with them by phone but email sometimes takes a couple days. I've not seen any of the hornady dies so I don't know if they are good or bad. The CH4D dies look good but for some reason they included a mouth belling die like you would need for a straight wall pistol case and I can't see using it....we use boattail bullets and don't need to bell the mouth. If you do get in touch with them you might suggest leaving that die out and dropping the cost. I think the set was $202 and the 338BR dies were much less.

I'll post some more info tomorrow after we test fire.

Frank

 

[biffj]

Re: .510 whisper gunsmith

Well the test went well, the gun works perfect. Recoil is pretty mild, especially compared to the .338 Lapua. The API bullets will still ding a steel plate (armor) despite the 1000fps velocity so shooting your buddy's nice targets is a no-no. The suppressor didn't get finished as I was unable to get the baffles done. We shot with the empty can on the end of the barrel and it was unbelieveably quiet even so. I'll get the baffles done in the next couple days and test again. I suppose I'll have to blow the $100 for another mag to modify so we can shoot 5rds at a time. Have to get a good load worked up too. I tried 25gr of N110 and 27gr of the same but velocities were all over the place. High was 1053 but a couple of the 27 gr shots were in the 850fps range. I loaded all 6rds with 2400 when we got home and I'll try that next.
We were shooting at 100yds with a scope zeroed for my 338 Lapua barrel and it shot a little right. I have a new Nightforce 5-22 X56 coming which will fit up and work a bit better and I'll get numbers for barrel swaps when it gets here. More brass will help this a lot too. Its hard to do much with just 6rds at a time.

Thats it for now.

Frank

 

[biffj]

Re: .510 whisper gunsmith

Barrel number 2 was finished for a friends rifle and we shot on sunday. The new barrel is a Brux Stainless cut rifled blank turned to fit and also threaded for a suppressor. Thanks to board member Spook for the blank. I finished the first suppressor so we got to test it too. We fired all 6rds with good result. Surprisingly the APIT .50 cal bullets actually lit up and all flashed on impact. There were also 3 M1 Incendiery bullets which were quite spectacular when they hit. Sorry I didn't get any pictures as we were a bit busy.
We also finished up the barrel for a friends Mauser 98 510 setup. There is still work to do fitting the extractor and follower work to feed right but we shot a couple rounds for test purposes and it worked well.
So 3 new 510's, or should I say 12.7 X 48's, out there now. Now we are just waiting for brass to get done.

Frank

 

[biffj]

Re: .510 whisper gunsmith

Here are the missing pics. Tan rifle has the new stainless 510 barrel with a suppressor made by me. The green rifle in the pic is wearing the .338 Lapua barrel with my suppressor as well. Both rifles were very quiet and earplug free shootable. Obviously the 338 bullets make a lot more noise at nearly 3Kfps but the rifle was nice to shoot and quiet. The 510 was nailing the targets at 250yds and very nice to shoot.

Frank