1. Attention: We have put together a thread with tips and a tutorial video to help with using the new software. Please take a moment to check out the thread here: Trapshooters.com Tutorial & Help Video.
    Dismiss Notice

Question on headspace, I think

Discussion in 'Uncategorized Threads' started by no5shooter, Jun 10, 2008.

Thread Status:
Not open for further replies.
  1. no5shooter

    no5shooter Member

    Joined:
    Jan 29, 1998
    Messages:
    453
    OK, I think my concern involves headspace measurement on a break-open gun. I've shot a BT-99 since 1972, and it's treated me well when I did my part. I found a 34" Full choke barrel for it, which locked up perfectly. The only glitch was the forearm hanger on the new barrel hung down just a bit, letting the forearm wobble a little - too loose. So I took the whole package, including the original barrel, to a well-known gunsmith who said he could alter the forearm hanger on the new barrel so the forearm would fit as well as it does on the original. When I got the gun back, the forearm does indeed fit well, but now there is a gap between the breech of the new barrel and the action. Not a big gap, but you can sure see daylight between the two parts! The original barrel still fits fine and the forearm attaches to the original just fine too. So my problem is definitely with the new barrel. Question one: Is a gap like I've described the problem I think it is? Question two: Any suggestions? I'm thinking the hinge on the new barrel is going to have to be built up and then re-machined to fit the action properly. It did when I first got it, so the gunsmith must have relieved that a bit in the process of fitting the forearm without altering the forearm latch. Thanks for any advice, folks. Jerry, in Oregon
     
  2. GunDr

    GunDr Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    2,913
    A "gappy" breech face is very possible when installing a used bbl to any break-open gun. With all of the fancy computerized machining centers in use for manufacturing firearms, a final fitting by hand is always neccessary. This is where the inconsistancies come into play.

    I know there are one heck of a lot of P-guns and K-guns out there that have small gaps in the breech faces because the bbls were not original to the gun. The question can be asked....is this bad??

    Well, yes and no. Having a gap small enough to still prevent the "no-go" guage from locking the gun, is fine. The "no" part would be if while firing a round the rim should split at the base. Not having a tight seal, the gases can escape, possibly causing injury to your eyes or arms.

    With regards to your BT-99, the cost of closing up this gap may be just a little more than you'd really want to stick into the gun. Tightening up the forend, by reworkin the forend lug on the bbl is a common fix on all break-open guns, and usually runs around $100. Correcting a gap...quite a bit more.

    Either the joint roll pin gets replaced, or the hook on the bbl gets material added to it and then gets recut. Some joint roll pins are pressed in, others are silver(hi-temp) soldered. Either way will involve having to reblue the receiver...adding to the cost of the repair. Browning does not sell new pins. I don't even think Browning would even install a new one at their shop. So, the new pin would need to be made by the gunsmith. Now, having this new pin installed and the used bbl fit to the gun, the original bbl will need to be refitted. Remember, there also will not be any engraving on the ends.

    My guess is if the job is done, you'd be looking at over $500 when everything is completed.

    My suggestion for everyone looking at a used bbl is to ask for a brief inspection period, take the gun to a competent gunsmith, and have him check the breech for a gap, headspace it, and then get a quote for the repair.

    A few guns are a little more "friendly" when it comes to fitting used bbls. Guns like the Krieghoff and Beretta offer overized screw-in pins. No need for pressing, soldering or reblung.

    A few here have sent their Perazzis to Giacomo for a joint roll pin replacement and bbl refitting. I sure they can tell you the cost of this mod.

    Doug Braker
     
  3. no5shooter

    no5shooter Member

    Joined:
    Jan 29, 1998
    Messages:
    453
    Doug, thanks for the info. What you say makes sense, so it's probably the case. First order of business will be a no-go gauge check, and I'll proceed from there. Might have a barrel to sell, who knows? Thanks again. Jerry
     
  4. redhawk44

    redhawk44 Member

    Joined:
    Jan 29, 1998
    Messages:
    552
    Location:
    Mendon, Mi
    If you do decide to sell it, how long is it?
     
  5. BDodd

    BDodd TS Member

    Joined:
    Jan 29, 1998
    Messages:
    3,594
    redhawk44, it was a 34" in the first post.
     
Thread Status:
Not open for further replies.