Rolling Block Question

[38-72]

I have a 1901 smokeless Rolling Block (7MM).  With the action closed, hammer down and then pulling on the breech block, the breech block rocks back leaving a gap at the barrel of several thousands. 

What can be done to close the gap between the front of the breech block and the barrel?
Is it possible to build up (weld) either the breech block or hammer to tighten up the action?

[Rangr44]

I would think someone shooting modern loads in it caused the axle/pin to bend.

The second thing I would do would be to replace both axle pins with ones made from hardened drill rod.

The first thing, of course, would be to check the lower half of both the breechblock and hammer for cracking - right where they're thinnest/weakest.

Hopefully, the axle/pin holes in one or both frame sidewalls haven't been pounded out of round.

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[lkydvl]

Lets check the headspace properly first before we get carried away.  Get a proper headspace gauge and see what the results are.  If the headspace is excessive then you can start checking for the various possible causes. 

I had a similar situation when building a couple rollers in 38-50 on 7mm receivers.  Had the barrel all machined and when turned in it had excessive headspace!  Some head scratching and rechecking measurements and lo and behold we found a defective caliper had given us erroneous readings.  That one went into the trash and a replacement gave us corrected readings which when applied to the barrel gave us spot on headspace.

In that case it wasn't bent or cracked parts but a poor barrel installation.  Check them all before you start replacing parts.

Andre`

[John Traveler]

You've been give good advice so far.

First, check for proper headspace using the proper headspace gages.

If you don't have access to headspace gages, you can use full-length sized cartridge cases and shims to check for casehead-to-breech block clearance.  It should be in the neighborhood of 0.005" to .0.008" before the block refuses to close and lock.

Lastly, check for bent block and hammer axel pins.

And NO, I would not even consider welding on the block or hammer support to remove the looseness.  That is just asking for trouble!

[bubba.50]

 if you need to replace any parts they can sometimes be found at: www.rollingblockparts.com they have some original parts and some new manufactured parts. good luck. i really love my old rollers. hope you get yours going, bubba.

[gunnut69]

I've seen a lot of stretched 7mm Rollingblocks. It may be the cartridge was a little warm for the action/metalurgy of the time. Welding would bujild up the parts but they would no longer be sufficiently hard... That can and will lead to serious problems. You may speak with Lee Shavers and see if he'll look at it for you.. He's in Missouri but I can find an address just now..CRS strikes again.

[Rangr44]

FWIW, a bent breechblock pin or cracked breechblock will give an excess headspace indication with a perfectly good barrel/chamber.

Headspace is something I would check if the breech appeared/operated as normal - which the OP states it did/does not.

I would respectfully advise not to let the cart get ahead of the horse.

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