Rebarrel

[Vek]

Question for you folks:

I went prairie dogging last week with my .280 (Rem. 700 BDL, yeah, too much gun, I know). Anyway, my uncle brought out his Chrony and I shot over it a few times. I was getting 2700 fps out of a 110 grain speer tnt moly. This is nearly 600 fps slower than my hodgdon manual says for the load used (59.5 gr. I4831, fed 210 primer). What does this indicate? Am I shot out? The thing has always grouped well for a pawnshop rifle (you can get sub moa with a bit of skull-dudgery). The manual got their numbers from a rem. 700 with a 24" barrel, and mine's a 22". I don't think that should account for a 500 fps difference. I have kicked around the idea of rebarreling with a Shilen and having them true the action and such. Is this worthwhile? This is a hunting rifle first and foremost, but I'm a big fan of unassuming rifles that shoot well. Also, I am wondering where i could find a source for laminated stocks (sporter-type). I like wood on a rifle. Thanks for your help.

Jerry V.

 

[Art Eatman]

Looking at the 26th Ed. of Hodgdon's book, it lists 100-gr & 115/120-gr loads. Reading between the lines and looking at the choices of powders and all that, I'd think you'd be getting around 2,900 to 3,000 with your load.

My book shows for H4831, with the 100-grain, a max load of 62.0 and a velocity of 3321. With 115/120, max is 60.0 and vel. is 3129.

The difference between starting load and max load seems rather small. Apparently this cartridge might be a bit picky? Dunno.

The two inches of difference in barrel length could cause you to be around 150 ft/sec less than their test loads.

Maybe your chamber is on the large side of okay; your powder scale could be reading heavy, or your chronograph could be off. Or all of the above BS.

However, if you're getting good groups, I'd hang on to what you have while you keep working on troubleshooting your overall system.

Damfino, Art

 

[Al Thompson]

What Art said. The truth is that chronographs are sometimes inaccurate. I wouldn't get wired up until you can confirm that velocity. Considering that the figures are so out of whack, my bet is that the Chrony is busted. But, you need to start eliminating the variables to be sure and getting on a different chronograph is the first step.

Not sure about the stocks - try Midway and Brownells.

Giz

 

[Unkel Gilbey]

Something to think about...

Concider the age of the components that you are using. Old powder and/or old primers might bring on the condition that you have referred to. Aging, different formula's, different lots of components all can effect the final outcome (velocity.)

There might also be a difference in the loading data that would bring this situation to light. What I mean is that if you are using a (let's say) 1950's era loading book, and recently manufactured powder - there is a chance that there might be a 'reduction' in theoretical velocities because the newer powder doesn't have the same 'moxie' as the older stuff that the data was originally worked up for.

I personally haven't seen this happen, but I wouldn't be too surprised to hear that it did.

If nothing else, it might give you some insight next time you go shopping for components...

Good Luck,

Unkel Gilbey

 

[Hutch]

I'd suspect the Chrony. I own half interest in one, and I have never been satisfied that it was accurate. It showed Fed .357Mag 125 JHP (the M&S favorite) exiting my 10" Contender barrel at a skosh over 2000FPS. Hmmmmmm....

 

[James K]

Loading manuals could never be wrong could they? Or exaggerate loads to keep turkeys from dropping in a little more powder?

Jim

 

[Southla1]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Jim Keenan:
Loading manuals could never be wrong could they? Or exaggerate loads to keep turkeys from dropping in a little more powder?[/quote]

Either that or the lawyers are writing the books now. Compare loads listed as maximum today to those of older manuals such as those printed in the mid 60's. I know that I ahve worked up to some of those mid 60's loads and they are fine in my guns. Go to todays manual and it makes you wonder. Some of the loads listed years ago and SAFE in my particular gun are up to 4 grains over max today.
Sure there can be differences but all the trends are like this.

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Carlyle Hebert