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COMPARING THE COMBINED EFFECTS OF,

BULLETS- POWDER- BARREL LENGTH

                                                                                                    

This edition of “Tech Notes” compares the effect powder and bullet combinations have on different barrel lengths.  We have all seen the articles where the writer hacksawed off the barrel from “way out there” down to just a nub (not with my guns pal!).  I have taken real 44 magnum handguns and a rifle and compared them in many different loads with different powders.  We go from a 4 5/8” barrel up to a 16” ported barrel on a Marlin 44 magnum rifle. The 4 5/8”, 6 ½” and 7 ½” barrels are Ruger Super Blackhawk’s.  The 5.5” barrel is a Ruger Redhawk.  The 4 5/8”, 5 ½” and 6 ½” barrels are all Magna Ported...With the exception of test #1 (an older test).  All listed firearms are fire lapped except the 7 ½” SBH, which has many thousands or rounds of jacketed ammo through it and shows the same effective velocities as similar 7 ½” SBH’s that are fire lapped. Data for each test was shot under similar conditions.  Many were shot the same day.

WARNING: SOME OR NONE OF THESE LOADS MAY BE SAFE FOR YOUR 44 MAGNUM HANDGUN/RIFLE.  DETAILS ARE GIVEN FOR COMPARITIVE PURPOSES, NOT AS AN ENDORSEMENT OF THE LOADS.   

TEST #1

BULLET	POWDER	WEIGHT	CASE	PRIMER
240gr LSWC	AA-2	8.0 GR	WW	FEDERAL 150
4” VEL	5 1/2” VEL	6 1/2” VEL	7 1/2” VEL	16 1/4” VEL
952	990	1021	1050	N/a

Notice how the quick burning AA-2 gives very little difference in velocity no matter the barrel length.  This is a trait of the quick burning powders with light charges.

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Test #2

BULLET	POWDER	WEIGHT	CASE	PRIMER
250GR LBT	AA-5	14.0 GR	WW	FEDERAL 150
4 5/8” VEL	5 1/2” VEL	6 1/2” VEL	7 1/2” VEL	16 1/4” VEL
1095 fps	1130 fps	N/a	1165 fps	1410 fps

This is an effective game load for some hunters.  Notice the fairly small loss of velocity, as the revolver barrels get shorter.  It does give a nice jump in velocity going to the 16” rifle barrel. Total velocity change from shortest to longest is 315 fps.

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TEST #3

BULLET	POWDER	WEIGHT	CASE	PRIMER
250 GR LBT	‘LIL GUN	26.7 GR	STARLINE	FEDERAL 155
4 5/8” VEL	5 1/2” VEL	6 1/2” VEL	7 1/2” VEL	16 1/4” VEL
1390 fps	1445 fps	N/A	1505 fps	1895 fps

If you want to make a 250gr bullet go fast, this is it.  All this powder has to go somewhere so the total velocity change is 505 fps with 390 fps just from 7 ½” to 16”.  The sealed breach of the rifle makes an unusually large difference with the comparatively light bullet and heavy powder charge.  As a side note, shooting this load in the 4 5/8” barrel is absolutely the loudest load I ever shot.  I was double muffed and it about blew me off the bench.  The 5 ½” and longer barrels were not nearly so abusive.

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TEST #4

BULLET	POWDER	WEIGHT	CASE	PRIMER
270 GR SP	H-110	22.5 GR	STARLINE	FEDERAL 155
4 5/8” VEL	5 1/2” VEL	6 1/2” VEL	7 1/2” VEL	16 1/4” VEL
1180 fps	1245 fps	1272 fps	1330 fps	1600 fps

In all the testing for this article, I had to include at least one jacketed load.  Well… sort of.  This bullet is the Speer plated 270gr.  It has pure copper plating instead of the normal, harder, jacket.  Bullet friction in the barrel is less than with a normal jacketed bullet and more than a lead alloy bullet. This load give a nice 270 fps jump from 7 ½” barrel to 16” rifle barrel.  Total velocity spread is 420 fps.

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TEST #5

BULLET	POWDER	WEIGHT	CASE	PRIMER
280 GR LBT	H-110	22.3 GR	STARLINE	FEDERAL 155
4 5/8” VEL	5 1/2” VEL	6 1/2” VEL	7 1/2” VEL	16 1/4” VEL
1185 fps	1245 fps	n/a	1300 fps	1585 fps

This load is on “load-swap.com”.  It’s pretty easy to shoot.  It reflects what I have so often seen with H-110 powder and LBT bullets.  That is, a 60 fps jump from 4 5/8” to 5 ½” and a 60 fps (average) jump from 5 ½” to 7 ½”.  Notice the almost 300 fps jump going from the 7 ½” revolver to the 16” rifle barrel. Total velocity spread is 400 fps.

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TEST #6

BULLET	POWDER	WEIGHT	CASE	PRIMER
290 GR LBT	H-110	23.5 GR	STARLINE	FEDERAL 155
4 5/8” VEL	5 1/2” VEL	6 1/2” VEL	7 1/2” VEL	16 1/4” VEL
1250 fps	1275 fps	N/a	1330 fps	1610 fps

This heavy bullet is a rocket out of these guns.  The velocity jump in revolver barrel lengths is less than expected.  The jump to the rifle barrel gives a handsome 280 fps.  Total velocity spread is 360 fps.  This is an easy load to shoot in guns that will safely handle it. 

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TEST #7

BULLET	POWDER	WEIGHT	CASE	PRIMER
325 GR LBT	H-110	21.5 GR	STARLINE	FEDERAL 155
4 5/8” VEL	5 1/2” VEL	6 1/2” VEL	7 1/2” VEL	16 1/4” VEL
1165 fps	1230 fps	1265 fps	1295 fps	1510 fps

Now we are into the “big boys”.  Look again and see the typical 60 fps jump going from 4 5/8” to 5 ½” barrels and 60 fps jump going from 5 ½” to 7 ½” barrels.  If you ever wondered about the velocity loss from Magna Porting, note how the velocity drops from 7 ½” to 6 ½”.  The 7-½” barrel is not Magna Ported but the 6 ½” barrel is Magna Ported with “dual traps” (that is a total of 4 ports).  The 30 fps drop in velocity includes the porting and a 1” shorter barrel. Also notice that with less powder to push the bullet there is only 215 fps gain from the 7 ½” revolver to the 16” rifle barrel.  Total velocity spread is down to 345 fps.

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TEST #8

BULLET	POWDER	WEIGHT	CASE	PRIMER
330gr LBT	H-110	21.0 GR	STARLINE	FEDERAL 155
4 5/8” VEL	5 1/2” VEL	6 1/2” VEL	7 1/2” VEL	16 1/4” VEL
1155 fps	1200 fps	N/a	1210 fps	1475 fps

This is a lot of bullet to stuff into a 44 Magnum case.  With a heavier bullet and less powder, this load begins to mimic the velocity spreads of AA-2 & AA-5.  Notice the total velocity spread is only 320 fps and most of that is from the jump to the rifle barrel.  I believe that an LBT 330gr LFN bullet going almost 1500 fps is likely to stop most anything that gets in its way up to 100 yards or so. 

                        I hope this is of some help to those of you interested.  The results listed above are very typical of hundreds of chronograph tests in my and others 44 Magnums. 

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