Non-consistant bullets

[e-bear]

I set out to load some 147GR Rainier plated HP 9mm bullets last night. However, it didnt take long to realize that the OAL was inconsistant. I was setting them to an OAL of 1.10 and some were coming out at longer lengths. After I loaded up 50 I counted 10 that were anywhere from 1.11 to 1.2. I dont want to set them deeper for fear of dangerous pressure spikes.

Today I guaged ten loose bullets from this lot and found a variation from .637 to .647 in length and 145.4GR to 146.6GR in weight. All were .354 diameter.

Just like to hear some thoughts on this because most of you guys know a good bit more about it than me.

In a 9MM is the OAL more important than the bullet seating depth?

 

[JimDandy]

Not knowing the 9mm front and back, both are important. If you have a small/tight chamber, you could be on the lands already if it's long. (This is a long shot, but something to pay attention to)

 

[e-bear]

WOW

Thanx Jim. I was hoping for a better response from posters here but it is what it is. I will just keep looking untill I get the right info.

 

[eldermike]

Bullets seat by process of pushing on the ogive curve on the bullet, we then measure them from the end. The process and the measurment don't match up.

The seating process is perfect with respect to how the bullet fits to the chamber of the gun. It's imperfect as to how the base of the bullet sits in the neck of the case.

 

[Brian Pfleuger]

Bullets seat by process of pushing on the ogive curve on the bullet, we then measure them from the end. The process and the measurment don't match up.

I haven't seen a factory seating plug yet that touches the ogive. They're not usually flat, touching exactly on the tip, but they don't come close to the ogive, that I've seen.

However, the greater point is a good one. You should get a bushing that's as close as possible to 0.355", zero your calipers on it and see how much the bullets vary.

Distance from the rifling and seating depth are what dictate pressure. If the bullets are reasonably consistent on the ogive and not at the tip, the simple solution is to use the closest you can find to a 0.355" (9mm or 11/32) drill bit and drill out the seating plug so it DOES seat from the ogive.

 

[JimDandy]

Hornady made a whole set of em.

 

[eldermike]

Brian,

I have most of my seaters either modified or purchased to push on the curve. In fact there is nothing else consistent in the manufacture of a bullet other than weight and shape. The least important thing is it's length.

 

[e-bear]

Thank you, eldermike and Brian, I was and still am wondering about the variations in Plated bullets from Rainier.

Labelled as 147GR but actually 145.4GR to 146.6GR. I did not weigh any that weighed 147GR. and all were.354 diameter not .355 diameter. Is this normal in bullet manufacturing?

As far as the variations in length of bullet is concerned I am afraid to set the bullet deeper to achieve the proper OAL.

Maybe its just me but I would rather err on the side of caution and be perceive as a dummy than be a dummy and cause a mishap at the range.
Thanx again for your input.

 

[BigJimP]

The variation you're seeing in electro plated bullets...especially in Rainier is common / in fact I would expect a bigger variation in weight in Rainier's bullets...( in 147 gr....maybe 3 or 4 gains of variation )...in weight than you've been finding ....and some variation in shape is common. But they're probably just fine for range practice.

Berry's plated bullets are thicker ...and I think you'll see less variation in them / or at least I've seen less variation when I've used them vs Rainier bullets.

Your best tolerances / most consistent weights, in my experience, will be seen in true jacketed bullets...like Montana Gold.
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But all of these bullet mfg's mass produce their product....and we're not talking about "airplane parts" ....or "artificial heart parts" ....where tolerances are much tighter...bullets are an expendable product.../ while all mfg's do the best they can ....you're always going to find some variation in a case of bullets...regardless of what grain or style bullet you select.

 

[BigJimP]

Overall length on the cartridge is a little harder to evaluate...and depends to some extent on bullet shape. I tend to load my rounds - in whatever caliber I'm loading ....on overall length / based on what I measure in terms of factory loads with similar weight and shaped bullets.

I also use a case gague ( you can buy them from Dillon and other sources ....but I use the case gague as a max overall length...and as a quick gague, drop the finished cases in and out ...if they drop in flush and drop out easily ...then I box them up. This will help you pick up an occasional primer that is too high, or a small crack that opened up in the case when you seated the bullet, or a nick of the base of the case ---all of which will show up as a feed issue. You can then reject that cartridge...pull the bullet and reclaim the components...

( You could do the same thing - by taking the barrel out of your gun / using the barrel chamber as a case gague )...but I find a good case gague allows me to run my reloads thru the tightest chambered guns I have ( like high end 1911's in 9mm ) as well as more production guns like Sig 239's , Sig 226's...with no issues.

 

[eldermike]

OAL data is not found in all manuals and I stopped recording it in my personal data long ago. The tip of a bullet is not a proper datum point unless you are using a tape measure to take the data.

On rifle ammo I have found it very easy to pull the firing pin and use the gun and bolt as a gage. Without the effect of springs I can feel the lands and bullet touching. I can decide from there what I want to try. I can go longer and force the bullet into the lands or I can go shorter. But I don't care where the point ends up as long as the finished round fits the magizine.

On pistol ammo I simply make sure I am off the lands with the bullet seated, and proper fit to the magizine.

OAL will not tell you both answers, only the magizine fit.

 

[e-bear]

Thanx guys. I guess I will set the bullets a bit deeper untill the desired OAL is acheived.
Happy shootin.