Gunsmithing AR-15 WSSM conversion mag question w/ SOLUTION!!!

[Hellbender]

I'm building a 243 WSSM and the factory AR-15 (NOT AR-10 ) mags are modified in the following way...

The Mag catch hole is raised by .080 in. (lowers the lips by this amount because the bolt & carrier is different/larger diameter). All the other mods done to the mags I can easily do in my shop (feed lip widening, follower cut, etc.)

As this is going to be a tactical competition rifle, (this would not be a problem on a hunting gun) I may need to rest the mag on a support sometimes and this will cause a possible malfunction, as the elongated mag catch hole will allow the mag to be pushed up by .080 inch, possibly striking the carrier ass'y...........

There are several ways I can fix this, but the easiest and best way would be to find some mags with a proper hole location.

Any mags on the market with a raised hole location ...ie 6.8, .458, etc, etc?????

My other options are.......modify rifle bolt catch, or.....make a ring around the mag that will hit mag well opening to stop overinsertion, or.... try to weld on a mag (SS wold be best) build this area up and remachine it to proper size, or ......any other suggestions?

Thanks for any and all replies.

 

[CastleRocker]

Re: AR-15 WSSM conversion mag question

If you are looking to purchase magazines that will work with the 243 WSSM.....why not just buy them from Olympic Arms? They have been manufacturing WSSM uppers for a long time now, and I've purchased extra magazines from them in the past. Also, you could contact Mike Milli at DTech, (Dedicated Technologies), as he also builds custom WSSM uppers.

Just a thought

 

[Hellbender]

Re: AR-15 WSSM conversion mag question

I got these mags from Mike, and he said the Olympic factory mags are made the same way.....Is this not true, maybe he was mistaken?

I'm also going to try messing up a P-mag w/ some epoxy and an .080 SS spacer plate.

Thanks.

 

[GasLight]

Re: AR-15 WSSM conversion mag question

Another answer that might work, is to make a mag stop on the outside of the magazine that will contact the mag-well at the right depth. I have seen this done on other platforms, and think it could work well for this application... Something as simple as a small spot of JB Weld or something could work on the cheap. Just insert the mag with the elogated hole, pull on it downward, and mark where you will need to create the 'stop'.

Dave

 

[GasLight]

Re: AR-15 WSSM conversion mag question

The mag on the right has the stops like I am talking about, keep the mag from being over-inserted:

 

[AZHUNTER]

Re: AR-15 WSSM conversion mag question

I have a 243 WSSM and am interested in seeing what ends up working for you. My thoughts have been to tig weld the magazine to raise the lower area of the catch and then regrind to proper fit. I just dont have access to a tig welder so I have never tried it.

Good luck,
John

 

[AZHUNTER]

Re: AR-15 WSSM conversion mag question

Here are some pics if it will help with ideas!!

 

[Hellbender]

Re: AR-15 WSSM conversion mag question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DebosDave</div><div class="ubbcode-body">Another answer that might work, is to make a mag stop on the outside of the magazine that will contact the mag-well at the right depth. I have seen this done on other platforms, and think it could work well for this application... Something as simple as a small spot of JB Weld or something could work on the cheap. Just insert the mag with the elogated hole, pull on it downward, and mark where you will need to create the 'stop'.

Dave </div></div>

Dave---That was one of the options I was considering, I was thinking of a "ring" clamping/epoxying/etc around the mag body....but there are some disadvantages to this, ie, would need to be fit to only one lower, mag pouches may hang up, etc. BUT, still may be the best solution, I don't know yet.

Thanks for the pics!

 

[Hellbender]

Re: AR-15 WSSM conversion mag question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AZHUNTER</div><div class="ubbcode-body">I have a 243 WSSM and am interested in seeing what ends up working for you. My thoughts have been to tig weld the magazine to raise the lower area of the catch and then regrind to proper fit. I just dont have access to a tig welder so I have never tried it.

Good luck,
John </div></div>

John
I really don't like the welding thing very well (Alum weld will be very soft, ie wear fast and may warp the mag body), but may have to do that, if nothing else works, BUT....

I believe I may have come up with something that may work, I have just put this gun together, and have to get a load worked up for a match this weekend, so it may be next week before I get to try it out......

I'm going to make a new, stronger, bigger "bump".....

First, measure the dimensions of the bump under the catch hole (in your pic, the width and depth (the amount it is raised from the flat of the mag body)), the height won't matter....I don't have a mag in my hand, but just for conversation, say it is .400" wide x .060" deep.

I'm thinking of removing the bump under the hole totally.....then take a strip of stainless steel the same thickness (say our .060") same width, (.400") and about 1.4" tall. Epoxy this to the side of the mag body in the correct location. Better yet, you may even be able to make a "backer" plate to go into the inside of the mag and screw (countersunk heads) the 2 plates together (sandwiching the mag body), then cut a little off the follower inside to fit around it. I think the interior plate would still be thinner than the ribs in the mag, so it should not interfere with the shells in the mag.

I'll post some pics when I get them done, I have 2 of the 7 round mags from Mike and I'm gonna make some 11 round mags out of some aluminum 30 round AR mags.

Brad

 

[Hellbender]

Re: AR-15 WSSM conversion mag question

Well, I got the mags done, and it was a lot of work.

Here is a pic of where the bolt carrier was hitting the back of the mags, because there was nothing stopping them from going in too far, I believe this was causing a lot of unexplained fliers. The gun would wad three out of five in a 1/4" group and then the other two shots would be out a 1/4-3/8" in any direction from the main group. When the bolt carrier contacts the mag body, it will change the seating force on the round (Sounds logical, anyway, we'll see).

Anyway, here is how I fixed them.....

First, I totally removed the raised hump on the mag below the mag catch hole, I did mine with a mill, but you could just as easily cut it away with a Dremel, files, etc.

Next cut a piece of steel 1/16" thick (14 gauge) X .400" wide X 1.4" long. I actually found some scrap the right size at my local steel supply. A piece of cold roll bar stock 1/16" thick x 3/8" wide could also be cut to length. De burr all edges.

Roughen up the area on the mag body and back of the plate where the plate will be glued, I used a rough stone on my Dremel tool.

Epoxy the plate in place, I used the mag catch (remove from gun) as a spacer to get the plate in the correct location and parallel, don't make it too tight, leave a little wiggle room (maybe .005"). Make sure the plate is straight between the ribs on the mag body. Use a Cutip and clean off excess epoxy both inside and outside of mag.

Let the epoxy set up.

Check mags for function in gun, work bolt carrier and watch for contact. If all works well, then...

Time to bolt them on permanently.

Round up some 3-56 x 1/4" long (or whatever, you will cut to fit anyway) screws and a tap and drill. (I only had 4-40, but the heads were a little thick, I had to grind them off, and more threads would be better.)

Locate your holes top and bottom and drill with your tap drill ALL the way through BOTH sides of the mag body. Then turn the mag over and CAREFULLY drill with a larger bit (for thread clearance size) through both sides of the mag BODY ONLY, NOT the steel plate you put on. This is so the bolt head will seat all the way and clamp properly. Then tap the steel plate to your bolt size.

Test fit your screws and make sure they are seating all the way, the heads should be lower than the ribs in the mag body for no interference. I ground these down a little more than the pic shows. Your allen wrench fits through the holes in the mag body on the opposite side of the plate.

Epoxy under the bolt heads and in the threads.

After epoxy sets, grind off the excess threads and hit the mags with a little black Krylon to make it all look good.

Now I can use my long 11 round mags as a monopod if I want to, with no worries!

Hope this helps some of you, most hunters would probably not worry and be satisfied with the weird fliers and would never rest their mags on anything to possibly cause a jam, but I think this platform has some real potential (esp in 6.5mm WSSM wildcat), but this mag problem is a major issue for a tactical rifle, this is one way to cure the problem.

Brad

 

[AZHUNTER]

Re: AR-15 WSSM conversion mag question

Thanks for the follow up Brad!! Let us know if it has any effect on accuracy now that the carrier is not hitting the mag.

 

[Hellbender]

Re: AR-15 WSSM conversion mag question

Well, I believe the mags were part of the flier problem, they certainly didn't help. But my main problem was I drilled the muzzle brake hole only .020" over bullet diameter, when I opened the hole to .030" over, the gun really started to shine. It went from a 3/4" to 1" gun down to a .3 -.4"!! This was my first brake install, and I'm still learning.

My son shoots this gun, he's 16 years old, and he has shot several 5 shot groups under .5 MOA at 3,4,5,6 and 700 yards (prone bipod), both in practice and at an F-class match last Sunday.

He was hitting clay-birds at 805 yards about 50-60% with a slight 3-5 mph wind in practice.

This mag fix was still a MUST as any pressure upward on the mag would cause an immediate jam.

Next winter I'm going to put a 1 in 8" twist bbl on it so we can shoot the heavy bullets, I think it will really be the ticket.

Here's the specs on the gun...........

Upper:
243 WSSM (Winchester Super Short Magnum) caliber
Olympic Arms WSSM receiver assembly and Bolt Carrier Group
Stainless Steel Ultramatch barrel, 23.5 inch length and threaded 5/8” x 24 tpi, 1 in 10 inch twist
Barrel Extension bedded to receiver and Gas block bedded to barrel
[Above unit was blueprinted, receiver squared, barrel headspaced and gas port timed, extractor modified and bolt lugs radiused and lapped to fit barrel extension.)

JP Enterprises aluminum adjustable gas block (clamp style)
(modified with add’l set screw to hold position on gas adjustment)
Badger Ordnance Stabilizer handguard
Holland SS Muzzle Brake, new model
Badger Ordnance Gen II Tactical Charging Handle Latch
Hahn Precision Scout Rail
Tactical Precision medium height “TSR” rings
Nightforce NXS 5.5-22x56mm MLR reticle, Mil-Radian knobs w/ Zero stops
U.S. Optics Anti Cant Device - Swivel
Harris 6”-9” Series “S” swivel bipod w/ Pod-Loc
Harris 9”-13” Series “S” swivel bipod w/ Pod-Loc (condition alternate)

Lower:
Tactical Innovations T15 Forged Precision Machined Receiver
Rock River Arms lower parts kit
Geissele DMR trigger group
MagPul Gen II PRS Precision Rifle Stock
Tubb Tactical grip

Brad

 

[500000KV]

Re: AR-15 WSSM conversion mag question

I've got a Olympic 243 wssm upper in a Tactical Innovations T-15 lower also. Did you have any problems with fitment of the upper to the lower?

 

[bvt]

Re: AR-15 WSSM conversion mag question

Congrats on the troubleshooting and homebrewed remedy. I love these kind of posts. But you gotta show us a pic of rifle and groups!

 

[Hellbender]

Re: AR-15 WSSM conversion mag question

Matt21-The front pin boss was a little tight, but no problems other than that......You don't want to get me started on the roughness and crudeness of all the Olympic parts, except the barrel. I've got a Magpul upper I am gonna machine to fit the next barrel.

bvt--I will get some pics up soon.

 

[500000KV]

Re: AR-15 WSSM conversion mag question

I had problems with the rear pin, took a little time but is fixed now, was curious if you had the same problem.

thanks for the info,

Matt

 

[tinhead]

Re: AR-15 WSSM conversion mag question

for those who have access to welding equipment(tig/mig),form a piece of copper water pipe or other similar thickness copper plate to fit the inside profile of your mag, clamp inside mag, weld,applying more than necessary filler metal,allow to cool,remove copper,grind to desired profile. stainless or carbon steel weld material will not adhere to copper, and will leave a reasonably smooth finish inside. not sure if this will work on aluminum,and warpage would be a concern. hope this helps someone.

 

[Hellbender]

Re: AR-15 WSSM conversion mag question

bvt-The pics I promised............

The Gun:

Brad

 

[Hellbender]

Re: AR-15 WSSM conversion mag question

The Groups...
This was shot prone w/ bipod at 300, 400, 500, 600, & 700 yards by my 16 year old son on a cold, 25-30 deg. day with a light wind from Left to Right. NOTE these are 6 shot groups, but I have both best 5 and total 6 measured, wind is a bugger.... sp260, a Hide member, also witnessed these groups as we were shooting together preparing for a match.

This was the first day out w/ this gun on a long range course and we were trying to get the dope figured out, so his elevations were a little off, but the groups were there.

 

[Hellbender]

Re: AR-15 WSSM conversion mag question

tinhead--Yes, the welding was another option I looked at, but it added several potential problems on the thin aluminum mags, and I hated to buy a $75 H&K SS mag to possibly ruin.

Thanks for the suggestion.
Brad

 

[long-shot]

Re: AR-15 WSSM conversion mag question

Guys this thing runs like a champ. I shot against it this past weekend, and there were no issues at all.

 

[Hellbender]

Re: AR-15 WSSM conversion mag question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: long-shot</div><div class="ubbcode-body">Guys this thing runs like a champ. I shot against it this past weekend, and there were no issues at all.

</div></div>

long-shot
Next match when you show up again with that new suppressor, better not turn your back.....That thing needs dropped or something, it shoots way too good!!! I haven't figured out what to do with the guy behind the trigger.....YET

Beat me by 1 stinken point!!!

 

[dahlgrenss]

Re: AR-15 WSSM conversion mag question

I am interested in making a WSSM AR15 in the 6.5 for long shooting. I spoke with one gunsmith and he said that the 6.5 140 grain with good ballistics were having a hard time fitting in the AR15 platform ( olgive is inside the neck). has anyone heard of any fixes for this issue?

also, I am trying to get an oly bolt and barrel extension so I can build my own (I have a CNC lathe). oly arms said they only sell the complete upper. any ideas?

Thanks

 

[Hellbender]

Re: AR-15 WSSM conversion mag question

Scott,

I don't think you will get a high BC 140 gr. to stay within the 2.26" OAL required by the magazine. You need to do some serious research on ogive lengths to see what bullets you can shoot.

What gunsmith did you talk to ?? I would like to speak with him.

You will need more parts than just a bolt and bbl extension, the bolt carrier and upper receiver are also different. I have a VLTOR MUR I am planning to modify to work, but all uppers cannot be made to work easily.

Talk to Mike Milli at Dtech.

Brad

 

[bunt0025]

Re: AR-15 WSSM conversion mag question

I am interested in making a WSSM AR15 in the 6.5 for long shooting. I spoke with one gunsmith and he said that the 6.5 140 grain with good ballistics were having a hard time fitting in the AR15 platform ( olgive is inside the neck)./quote]

I don't think you will get a high BC 140 gr. to stay within the 2.26" OAL required by the magazine. You need to do some serious research on ogive lengths to see what bullets you can shoot.

Sir,
I've got an Oly 243 WSSM with a 1in10 twist and it shoots any length bullet that you can fit into an Oly WSSM Magazine (which, as I understand, hold a longer OAL bullet than Dtechs). I don't know why anyone would want a 1in8 twist. 95 Berger VLDs don't hardly fit with the Ogive dropping away from the case mouth... which I imagine is why they don't have a good, steady 'feeling' when they are seated. 105 grain flat bases stick WAY down into the case, too, but still shoot fine.
Wouldn't a 6.5 Grendel or 6.8 SPC mag have the catch at a different location? I can't imagine that there isn't some manufacturer out there that has already mass produced the mag body closer to what the WSSM needs to float in the mag well correctly, therefore, leaving only the follower / feed lips to alter.
I think to get any more long range potential out of >257 cal WSSM case, one would have to move to the AR10 length magazine. I'd first look into magazine modification for the regular WSMs in AR10s before settling on a 6.5 WSSM for the sleek bullets.