375 Mercenary

[bigngreen]

Didn't ask the details, not really relevant to anything I do so didn't get more clarification.

 

[no worries]

Found out the other day that JGS could not ship 375 Mercenary reamers and gauges to individuals in Canada, Australia, New Zealand and Europe,

To remedy this I have submitted my JGS print to Manson and PT&G to get all bases covered and standardize the 375 Mercenary design with those reamer manufacturers

Mr. Dave Manson responded today, he transcribed the JGS reamer print, I triple checked it and it was spot on identical to the JGS print, my Canadian friends are happy to hear that Manson is making 375 Mercenary reamers and the first two reamer orders going to Canada have just been approved ,

Haven't heard from PT&G yet, maybe after the Holidays ....

For info on acquiring 375 Mercenary reamer/gauges, brass and dies send email to [email protected]

You bet it's ordered. I recived the conformation from Dave on Friday that its in process.

Everything should start showing up all around the same time then the fun begins gun)

 

[Swamplord]

Picked up the first rifle ever chambered in the 375 Mercenary on Christmas Eve 2016..........
fireformed a bunch of brass on Christmas Day and now making a modified case for the Hornady oal gauge and will start with load development

Rifle Specs......

33" 7.5 to 7 tw 8R Rock Creek CT contour barrel (1.350" shank for 6" then straight taper to 1.100" at 33")
Ashbury Precision Ordnance Saber VX action with Picatinny rail
4 port round Muscle Brake original by Centershot/Jim See from Bugholes
Nightforce ATACR in Nightforce Ultra Light rings
Choate Ultimate Sniper stock...............

yes, I know stock isn't quite right but it was all we had on hand that was gouged out to fit and bedded properly, this rifle is a combined effort of misc parts assembled in order to start the shooting ......

To those guys that get severely irritated by my "pretty pictures" ........ I always try to post pics of the actual things I am talking about, pics that are crisp and clear so folks can see what the heck I'm talking about, sometimes I will set up a cool background like the moose racks in these pics.......... don't know how to help y'all but request that you avoid my posts so my pics won't offend you......

 

[hubel458]

I like the thumb hole Choate stocks, our guys got 4 of

them in the 585 HE. Ed

 

[bigngreen]

Nice, looking forward to some data, securing a Lawton 8000 action and A-5 stock, I'll put a Rock on it as well just don't know length and taper I want to go yet, waiting to see the performance to choose a twist rate.

 

[Swamplord]

some important info......

For those of you wondering on the case length and loaded cartridge length........ chamber length is 3.115" and case length is 3.100" ........ I have compiled a list with Cutting Edge MTH bullets and will get the Chinchaga and Sierra bullets once I get them measured with the OAL gauge,

450 gr 4.924"
425 gr 4.816"
400 gr 4.709"
375 gr 4.603"
350 gr 4.502"
330 gr 4.373"
320 gr 4.325"
300 gr 4.241"

 

[TheFishBox]

How long do you think it will be before you are able to go out and collect some data on this thing? Do you think you will be close to the point of diminishing returns for the 375 caliber with this case considering available powders and the primers ability to torch all that powder off?

 

[Swamplord]

Dave Viers had no problem igniting a number of slow powders in his 375VM2 at 188 -190gr h20 case capacity other than some hangfires with US869 in near zero degree F temps, he had no trouble with it in warmer temps but we all know that powder is very temp sensitive,

The 375 Mercenary is only a couple gr more in h20 capacity so there isn't a problem igniting the same powders

Found some time to anneal the first batch of fired cases today after tumbling them overnight, loading them up for the second run, so far so good .....

 

[ohnomrbillk]

Found some time to anneal the first batch of fired cases today after tumbling them overnight, loading them up for the second run, so far so good .....

What annealer are you using?

 

[Swamplord]

I use the Benchsource annealer and set everything up with tempilaq to get the proper temps on the case neck/shoulder,

New Case Neck Annealing Machine

 

[Deleted member 71114]

The nice part about the Bench Source is you can use the standard plate to anneal these rounds, you don't need the special 50 Cal plate. The two torch heads pay off more on the larger diameter brass versus smalller casings - note the case spinner in tandem with the two torch heads gives a even heat transfer in the neck and shoulder area. The time is dependent on the torch positioning but for example I have my timer set on the Bench Source at 3.1 seconds on my 375VM2 brass which is very comparable to Swamps. I have had good luck burning H50BMG and RL50 with the 215M primmers I have some 20N29 I want to test with as well after we run a new reamer down my chamber soon, it was supposed to be done around the 21st of this month from JGS so I'm looking foward to getting it in the lathe.

I'm looking forward to seeing the Mercenary come together I think Swamp has a real winner here, only time will tell.

Cheers

 

[Swamplord]

The first sets of dies are being built for the 375 Mercenary. First step annealing the solid stock 1.5" diameter and 6" long. solid stock was brought up to 1700 deg then slowly brought to 1400 deg. and held for 2 hours. then slowly dropped down over a 12 hour period.

The dies will be color case hardened after done, will be nice looking and have blues, golds and grays in color just like the old winchesters and colts are...

Finished dies will be 1 1/4-12 to fit presses that accept that size by removing the press top bushing and installing dies in directly, presses with at least 4" clearance from top of shell holder.... such as the RCBS Supreme Rock Chucker, Redding Ultra Mag and Big Boss ll and similar,
the RCBS Ammomaster ll press can also be used with these dies by installing the 1 1/2-12 x 1 1/4-12 press top bushing available from CH4D, see attached pic of item highlighted in red.......

 

[Swamplord]

heads up to the guys that expressed interest in a 416 and 338 Mercenary, reamers are now available at JGS, send email to [email protected] for info to get your very own reamer...

 

[THEIS]

heads up to the guys that expressed interest in a 416 and 338 Mercenary, reamers are now available at JGS, send email to [email protected] for info to get your very own reamer...

Hello

Glad to see you protect your time and investment by not having all the appropriate dimensions released publicly and having the reamer marked "proprietary".
Sad to say but the dimensions will eventually be publicized and others will "tweek" them for themselves but the route you are taking will at least slow that process down some.

There are a few major weapons and ammunition manufacturers OCONUS (With Complete ITAR, US Dept of State and US Dept of Commerce "blessing") following this progression and will contact you at appropriate time.

THEIS