45-70 BUFF Classic?

[HOGBUSTER1]

I was at the range today, and someone had a H&R BUFF Classic 45-70 with the long BBL & peep sights. It seemed to be pretty accurate at 100 yards with 300gr bullits. He said he had some hand loaded 500gr cast bullets that averaged 1800 FPS with 4198 powder. He offered to let me try a couple and I refused. Im kind of peculiar that way, when it comes to other peoples hand loads, if you know what I mean. Anyhow, After the first 500gr bullet he shot I noticed that the rifle broke down just as iff he had pressed the release plunger. It did it agin with the second shot and so on and so on, until he ran out of shells. Now I know this is not normal and I went out of my way to inform of that. But he seemed convinced that there was nothing to worry about. I have owned three H&R RIFLES and can tell you, I have never had one break open upon fiireing. I have had one or two, not want to egect the brass. But thats another story!
Is this problem with the BUFF Classic normal, with heavy bullets?  Do you think the frame may be streaching, which will eventually lead to a cracked frame? Just currious! I have never seen this before. Or was I out of line?
Thanks

[henry1]

Most handi guns that do that "break open upon firing" do it due to a bad latch engagement. Its a simple fix really if your a diy type or you can send it in and h&r will fix it. I have never heard of a BC doing it. None of my h&r's have ever had this problem but i have heard about a few folks on here that have had the problem. I love my BC and it has never given me any trouble. If your on here alot you will sooner or later see some dressed up BC's! It is one of the "must haves" in anybodies h&r collection. Hope this helps!
Hank.

[quickdtoo]

Pop opens can be caused by several things, most aren't safety issues since it doesn't happen until well after the pressure is long gone, the fixes can be found in the FAQs or with a trip to H&R. It shouldn't continue to do it though, it's kinda disconcerting when that hot case hits ya in the forhead if it's an ejector, extractors won't hurt ya tho. 500gr at 1800 fps is well within the capabilities of the frame, that's right at 40kpsi with the 535gr Piledriver, a top levergun load.

I have two BCs, one is rechambered to 45-120-3¼" Sharps Straight, both are very accurate. John Boy shoots his at 1000yds, there's a long range thread back a page or two.

Tim

http://beartoothbullets.com/open_sight/archive_open_sight.htm/21

http://hr1871.com/Firearms/Rifles/buffalo.aspx