Any info on the real "Thumper" ?

[lathedog]

I was recently reading Jeff Cooper's "To Ride, Shoot Straight, and Speak the Truth" and it appears he had an actual prototype for "Thumper".

Thumper was his idea of a handy carbine in .44 automag caliber for military use, applicable to other use with similar criteria, that relied on bullet mass and diameter more than velocity to achieve results.

I notice many of the big bore AR-15 chamberings perform the same role, and at least one maker refers to "Thumper" in their marketing.

The point of all this was to ask if anyone has any more actual info on the real and original Thumper.

I have done a few internet searches with no joy.

Anyone have a picture, or a link to a picture, or any sort of technical info beyond the generic single paragraph from the book?

I'm slightly fascinated by the design and operation of the original, as briefly described by Cooper in his writings.

 

[garyhan]

To the best of my knowledge, "thumper" was a concept that has not been produced. Cooper's opinion was that the M16 was not a proper base for thumper.

gary

 

[bogie]

Since MO has allowed suppressors, I'm considering a .45ACP (variant - probably one of the "long" versions) version of the Delisle carbine - a bolt action rifle, suppressed barrel, shooting a big ol' fat bullet...

If I can run 250-300 grains of JHP at around 950 fps, that's good, given an understanding of how ballistics works, out to past 200 yards.

Why .45ACP variants? I'm figuring a cartridge that will hold a .451 bullet that will fit a .308 boltface. And since I'm figuring subsonic, I'm not figuring the long pointy bullets.

So what is the hottest .45ACP variant?

 

[Jim Watson]

How varied do you want your variant to be?
.45 Win Mag (the Wildey round) would be simple.


I never got the idea that there was a Thumper prototype in existence.

 

[lathedog]

I don't have the book in front of me, but the narrative claims that a prototype was shown to two different manufacturers and they were not interested. Could have been drawings, but I re-read the paragraph and it really seemed to indicate a functional prototype.

While googling for info, I ran across a colum that Cooper wrote on the subject an mentioned someone making a big bore AR. This was back before 2000 IIRC. I thought "Oh, here it comes", but he really didn't go off on the inadequacies of the AR platform. In retrospect he always seemed more negative of the original chambering than the platform.

Anyway, I guess I am getting the point that if I have real interest I should get an AR based "thumper" or learn to live without.

BTW I prefer a .451 (.452?) bullet rather than a .429; not sure why but I like to keep it in the 45 family.

 

[UnTainted]

Courtsey of Accuracy Systems:
http://www.ar-10-rifles.com/index.php

AR-10 in 450 Marlin.
Savin' the pennies!!!

Of all the AR thumping, which may or may not be the best way to go, I 'd say this would be the thumpin'-massa'

 

[UnTainted]

course that wasn't what you were looking for....

my bad

 

[CBS220]

Now that's wild!

Can't say I'd want to tote that around, though.

 

[ctdonath]

seemed to indicate a functional prototype

Any further info on that?

 

[ugaarguy]

Why .45ACP variants? I'm figuring a cartridge that will hold a .451 bullet that will fit a .308 boltface. And since I'm figuring subsonic, I'm not figuring the long pointy bullets.

Your figuring is correct, .45 ACP and .308 Win use the same shell holder for reloading.

So what is the hottest .45ACP variant?

45 Win Mag. You can make brass by trimming .308 brass down. It's usually considered best to do this anyway because you'll get the thicker case web to help handle all the pressure.

 

[db_tanker]

45 win mag brass is also sold by Starline as well as Winchester still making two factory loads for it, IIRC. correction...they only make one now...260 gr HP at 1200 fps at the muzzle.

I seem to remember a manufacturer making an M-1 Carbine that was chambered in 45 WM but never really pursued that. I had a 10" 45 Win Mag as a Contender pistol. It would do everything a 44 Mag could do. Only drawback was that as a single-shot the rimless case kinda made it a PITA over my 14" 44 Mag.

For an auto-loader though, it would be a blast IMO.


D

 

[mainmech48]

The only mention that I can recall is of an outfit, in Illinois IIRC, who had come up with a conversion on the M1 carbine to .45 Win. Mag and, I believe, also a 10 mm prototype to try and prove the concept's feasibility.

I may be mistaken, but I believe that it was in a column the late Colonel wrote about his test firing sessions with a prototype.

It's been a long while, but I believe that his conclusions were generally positive. It was mentioned that the cost was quite considerable and that the very limited magazine capacity dictated by having to modify GI 15 and 30 rd. mags to the much fatter rounds was a real drawback.

Hope this is of help.

 

[Jim Watson]

I remember the gunzine articles about the .45 Win Mag conversion to the M1 carbine.
Reading between the lines a bit, it seemed like they had a rather narrow operating range between action function and kaBoom. The factory loads were fine, but anything else was doubtful, one way or the other.

Many, many years ago there was an outfit that was going to offer box magazine conversions for the Ruger .44 carbine, and even .357 conversions to match police revolver ammo. Never materialized, though.