HKPRO Forums banner

1 - 13 of 13 Posts

·
Registered
Joined
·
872 Posts
Discussion Starter · #1 ·
I have a specific request, could any one please post their pictures of a build that has used PTR and/or FMP Re-Enforcing Rails.

PTR Re-Enforcing Rails look to be constructed completely different then RTDS and/or IGF Rails.

Adam Webbers page shows FMP rails but they kind of look like PTR’s??

For those that have used these on their builds did you pin them to the trunnion

I have heard that BIG 50 will be installing them on a build for The Great 308.

Thank you in advance for any and all responses and pics
 

·
Registered
Joined
·
1,276 Posts
Hi Robert. Here's a few pics of a friend's rifle I rebuilt about 3-4 years ago. He opted to use the JLD style rails instead of Ralph's (RDTS). As you can see the top edge of the welds are bigger. The reason being the rail does not touch the top surface. If you're gonna put together a nice looking and shooting rifle, I'd go with the RDTS rails.





I'm not sure if he's ever put rounds through the gun since it was rebuilt. Oh, by the way...the trigger pack was sent to Bill Springfield for a trigger job. The pack came back in a week. Very noticeable difference.
 

·
Registered
Joined
·
1,361 Posts
they actually dont look half bad, considering their price. the picture on JLD's website is a little misleading but they look like they would work out if you dont plan on doing a factory type build, you cant beat 25$ versus 195$ for an RDTS set
 

·
Registered
Joined
·
872 Posts
Discussion Starter · #4 ·
Thanks JFK

Thank you JFK


That’s what I was looking for,

As I understand it some builders do not pin the trunnion.

• Have any of you noticed if they pin the trunnion with these types of re-enforcement rails.
• Would you additionally pin the trunnion extension such as the IGF Trunnion extension and/or only the trunnion.

Please note that I’m unaware if these rails extend far enough to facilitate this possible prerequisite.

Once again thank you all in advance.
 

·
Registered
Joined
·
1,276 Posts
I'm not sure about pinning the rails to the trunion. The RDTS rails have a small hole which I TIG welded to my receiver.

The JLD rails are not long enough to extend past the rail slots towards the trunion. The JLD rails will have to go into your receiver just like the pics I posted.

The extension is usually welded to the existing trunion. I've never heard of anyone just sliding the extension into place and leaving it as is. My RDTS conversion does not have a trunion extension, but the forearm locks into place pretty solid.
 

·
Premium Member
Joined
·
8,629 Posts
A related question to the trunion extension -

Is it also a press-fit, like the trunion? If so, it seems like it would have to be welded into place (and perfectly aligned first) before the barrel is pressed in.
 

·
Registered
Joined
·
1,276 Posts
The IGF extension fits onto the front ledge of the existing trunion. The fit can be anywhere from tight to just snug, from trunion to trunion. You can slip the extension over the barrel and tap around the circumfrence with a wooden dowel to get it into place.

The trunion extension does not support the barrel. I TIG welded mine in three spots during install. I would not just press the extension into place because it will probably come off after repeated firing.
 

·
Registered
Joined
·
1,135 Posts
The IGF extension fits onto the front ledge of the existing trunion. The fit can be anywhere from tight to just snug, from trunion to trunion. You can slip the extension over the barrel and tap around the circumfrence with a wooden dowel to get it into place.

The trunion extension does not support the barrel. I TIG welded mine in three spots during install. I would not just press the extension into place because it will probably come off after repeated firing.
JFK I bought the IGF trunnion extension for my build. However since it does not offer any additional support to the barrel would I be better off using the BMP PSG1/MSG90 trunnion? Does it offer additional support for the barrel?

http://www.shop.black-market-parts.com/product.sc?categoryId=3&productId=7
 

·
Premium Member
Joined
·
8,629 Posts
The IGF extension fits onto the front ledge of the existing trunion. The fit can be anywhere from tight to just snug, from trunion to trunion. You can slip the extension over the barrel and tap around the circumfrence with a wooden dowel to get it into place.

The trunion extension does not support the barrel. I TIG welded mine in three spots during install. I would not just press the extension into place because it will probably come off after repeated firing.
It doesn't support the barrel? What is its purpose if not to support more of the barrel? Or does it support the barrel on a real PSG1 barrel, just not on a 91 barrel?

I've never seen one up close and personal so I'm not really clear on its purpose.
 

·
Registered
Joined
·
1,361 Posts
the black market parts trunnion does add support to the barrel, its a very solid and well made piece (surprisingly) I'm using one on my build so is
11CABN,

just as a heads up though the hole for the charging handle pin on a JFK cocking tube doesnt quite line up with the slot on the side of the BMP trunnion, its not a big deal and you can still get to the pin hole but if your a perfectionist it might bug you, jimmy makes the tubes using an IFG extension as a template and the hole lines up perfectly on those.

the extension is really only good to make it look correct and have some extra support to the hand guard

the BMP trunnion is a solid piece of steel and fits really well and adds extra support to the barrel.

in about 30 days me and 11C ABN will be welding togeather out rifles and will have a slew of pics to post, so if your interested in how it will look installed keep your eyes on the boards
 

·
Registered
Joined
·
1,135 Posts
Hello Paul123 I just want to make sure I understand you completely. I have one of the Top Notch parts MSG90 barrels and I am planning on using a regular HK91 bolt, bolt carrier and locking piece.

1) Does the BMP PSG1 trunnion work with a standard bolt or is it for a MSG90/ PSG1 bolt?

2) Would it be easy for Big 50 to make the JFK MSG90 cocking tube work with the BMP trunnion?

I was really hoping to make the most stable shooting platform possible so I think I would like the added support offered by the BMP trunnion. Do you know if anyone has tested the hardness on the BMP trunnions?

I can't wait to see the pictures of your and 11C ABN's builds.

My build is on hold for a little while I will be getting married on 10/20/07 so my wallet is getting a little thin.
 

·
Registered
Joined
·
1,361 Posts
the BMP trunnion will work with a standard 91 bolt, carrier and locking piece.

a JFK cocking tube will work with the BMP trunnion just fine but like i said in my previous post the little hole on the side of the cocking tube for the charging handle retainer pin does not quite line up perfectly with the slot cut into the BMP trunnion to gain access to the pin hole with a punch, you can still get to the hole fine it just looks off. im useing a JFK tube for my build and a BMP trunnion I dont see a need to change the hole location.

as far as hardness of the trunnion go's i've never had it tested but i've never heard of any problems with those or any other ones that T bailey makes. i would'nt worry
 

·
Registered
Joined
·
1,276 Posts
It doesn't support the barrel? What is its purpose if not to support more of the barrel? Or does it support the barrel on a real PSG1 barrel, just not on a 91 barrel?

I've never seen one up close and personal so I'm not really clear on its purpose.
I believe the purpose for the IGF support is to give the forearm more "meat" to hold on to. I checked the IGF extension and an Urbach PSG1 barrel and there is a difference in the sizes. The extension can easily slide over the barrel (from the muzzle to the front face of the trunion). The ledge of the trunion and extension piece fit snug. It does not support the barrel.
 
1 - 13 of 13 Posts
Top