10 grains (bullet wieght) difference in .38 Spl?

[John Joseph]

My chosen factory load is 158g LSWC. Fixed sighted .38 Spl revolvers such as my J frame are optimized for shooting 158 grain projectiles.
In preparation for the 2018 ammogeddon here in CA I picked up a used Lyman bullet mold which lists the LSWC as 150 grs.
There isn't a lot of difference in point of impact between 158 and 150g bullets, I've discovered.

In order to conserve the lifespan of my brass, I was thinking of loading 148 WCs, "only" 2 grains less than the 150 grains and would allow me to use a taper crimp so as not to overwork the brass cases.

So far, so good.

When the Air Guard Security personnel qualified on the same range I used to shoot at, I obtained several boxes of Winchester Match 148gr HBWC from them---they shot better scores with their S&W M-15 using 158g LSWCs. This was in adjustable sighted revolvers sighted in to shoot 130gr military ball. So I'll assume a 28 gr difference in bullet weight was acceptable, so my 158gr to 148 gr variance of only 10 grains shouldn't appreciably change the point of impact, especially at snub nose ranges.

So far, so good.

In other calibers, I've noticed considerable shifts in the POI, most noticeably going from 240 grs to 180 grs (60 gr variance) in .44 Magnums, and 230gr to 180 grs (50 gr variance) with the ,45ACP

Comparing factory .38 spl. 158s vs factory 148s, they seem "dead on" in terms of POI at 9, 17, 25, & 50'

This is 5x the amount of projectile weight difference in my .38 Spl. situation, so there should be no trouble with the POI shifting, right?

My question then, is there something I'm missing or overlooked here?

 

[Starter52]

I have found that fixed sight .38 revolvers will shoot roughly the same with either 148 grain or 158 grain bullets provided the MV is equal.

With a 2" barrel, at close range, I can't see any problems.

I shoot a lot of wadcutters and never bother to change the point-of -hold when shooting at 21 feet or less.

Hope this helps.

 

[mdi]

Conserving lifespan of 38 Special brass is not really a problem. I have reloaded some 38 brass mebbe 25 times over a span of 6 or 7 years (I don't shoot every day). I roll crimp all mine, even the DEWC I use in my house gun (150 gr. DEWC over a hefty load of W231). I know some folks are thinking 10 to 20 years for keeping shootable brass, but my remedy was to stock up on brass and components (38s are easy to find and cheap so amassing a couple thousand is easy).

I've normally kept my reloads' bullets to "standard" bullet weights (148/150 for wadcutters in 38. 158/160 gr for SWC and RNFP in 38/357 and 240/250 for SWC in my .44s) so change of POI with my fixed sight guns isn't a problem, or at least I don't notice it. I have noticed some change in POI, not with bullet weights so much but with powder charges. I think if I were in the "ammogeddon" situation, I'd find a load that worked well in my guns and assemble a bunch...

This CA craziness is the major reason I escaped CA the day after I retired...

 

[Sunray]

"...the lifespan of my brass..." Is about the load used, not the bullet weight or the kind of crimp used.
WC's are usually pure lead and sometimes swaged. 158 SWC's are not. Max loads of Bullseye aren't a whole lot different. 799 for a 148 vs 841 for a 158, but most people use 2.7ish for a 148 grain WC, more for a cast 158. Whole thing is more about what you're doing with the .38 than anything else.

 

[243winxb]

Velocity makes the difference, not the weight of the bullet. IMO.

With iron sight, on a 6" revolver, using a 6 o'clock hold, same loading. The bullets should hit close to the 10 ring. This is using Precision Pistol targets at 50 feet, 25 yards and 50 yards.

The black bullseye on the targets gets bigger as the distance increases, allowing for the rise of the bullets.

3.7 gr 700X in 38 special with 163 gr home cast. Mould listed as 158 lswc.

 

[Bart B.]

Heavier bullets in handguns cause more muzzle rise than lighter ones with the same peak pressure. Velocity is usually slower. They typically shoot higher. Not much with only a 10 grain difference.

Same with rifles but on a smaller scale.

The black bullseye on the targets gets bigger as the distance increases, allowing for the rise of the bullets.

Are you sure about that? NRA reps have always said bullseye's are bigger as range increases so they appear the same size and sight picture looks the same. I've always had to come up a few clicks on handgun rear sights as range increases; bullets start falling as soon as they leave the barrel. Fixed sights strike a happy medium.

 

[GooseGestapo]

With increasing bullet weight, you'll see a rise in the bullet impact on the target. This is due to the greater recoil impulse and longer barrel time. A 10gr bullet weight change won't matter much. Go to a 95gr bullet at a much higher velocity and impact may be more than a foot lower at 25yds.
You also have to figure in a change in windage due to a difference in barrel torque imparted by the rifling twist.
This doesn't apply to recoil operated handguns such as a M1911. The bullet exits the barrel before the slide reaches its rearward travel, transferring the recoil to the frame. However, barrel torque still can affect windage. Hence, practically all pistols have at least drift adjustable rear sights.

FWIW; I've got some .38spl brass that has been reloaded over 100 times. However, I mostly shoot cast wadcutters or semi-wadcutters with taper crimps. Cases fail eventually by neck or side splits at the cannelures.