Question On 9mm OAL

[alamogunr]

I'm going to be reloading 9mm for my grandsons and want to be extra careful about the load. I have intended to get into powder coat but haven't yet. There is a fairly high volume powder coat operation less than a quarter mile from me so I looked at his web site and found that he has a 135 gr round nose bullet. Since I have two MP 135 gr molds that I haven't used, I thought that I would buy a quantity to reload for the grandsons. By the time these are used up I should have gotten my feet wet with PC.

The caster/powder coater had a load of 3.5 gr Bullseye on his site as a recommendation. My problem is that nowhere in the manuals is there a load for 135 gr or recommended OAL. Since we are constantly warned that seating too short can raise pressures drastically, I'm wondering if there is a method for determining safe OAL for this bullet.

I'm hoping that I can get at least one of their guns to try function with a reload before I load a large quantity. As I mentioned, I don't want to take any chances with their loads. Any help would be appreciated.

[contender1]

" My problem is that nowhere in the manuals is there a load for 135 gr or recommended OAL."

Funny, most manuals do list a Maximum C.O.L. I just pulled an older Hornady manual off my shelf here,, (#8) and under the opening page of info it lists a Max C.O.L. (Cartridge Overall Length) of 1.169.
And when I look at the heaviest jacketed bullet they show,, a 147 grn bullet, they list a COL of 1.100 to 1.165 depending upon bullet selection.
I'd use the 1.169 as a MAX,, and start seating it just a bit under that to find the best load, that also chrono's in the safe range for the bullet weight.

[alamogunr]

Thanks! I sort of got tunnel vision and concentrated on overall length being dependent only on the bullet being used. I hope I can get a chance to chrono overall length's progressing from max to somewhat under max. Hopefully, one or more will reliably feed and give a velocity close to expected for the load being used.

[Jniedbalski]

3.5 gr of bulseye works very good. That is what I usually use.I just use max overall length or mag length and load .010 shorter . If that dosent do it .015 usually works.

[dimaprok]

Here's how I determine seating length for my 9mm bullets. My guns have pretty short throats so anything past ogive where driving band starts at .357 I can extend maybe another .025" max before it starts to hit rifling.

Trying to get proper seating depth with another bullet won't do you any good unless its exact same bullet as one you're going to cast. I have MP 135gr mold also. At about 1.1" its driving band is flush with case neck. Since my seating depth varies I aim between 1.005 and 1.115.

As far as powder charge I start low and step up in .2gr increments until I get reliable feeding and extraction and than add another .2gr to compensate if my powder measure swings I get reliable rounds. Each gun is different, my Ruger PC9 will shoot anything even starting charges and cycle. My Canic needed a lighter spring from start and likes medium/high charge.

Another thing to consider with kids they will induce FTE with same rounds that shoot fine for me. It has to do with how firm you hold the gun so make sure it shoots fine in your hands before you blame the ammo.

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[DHDeal]

John, don't forget to do the plunk test before getting set on any particular OAL. I had to adjust a few times before I set my SQDB for a bullet in Gen5 19's. It was a shorter OAL than I was expecting. You can play with the powder charge once you have the OAL.

Hopefully for you their 9mm's are the same model....

[alamogunr]

I do a plunk test whenever I set up for a new load or cartridge. I plan to do it for their guns also. Both if I can get hold of them even though they are both the same model. While I'm at it I'll also check my 9's out.

Whenever I start loading a new cartridge or boolit, I usually check it in a "Max Cartridge" gauge. I have a Midway set that I bought over 20 years ago. I don't depend on them exclusively but they are an indication if I'm in the ballpark.

I'm not too worried about FTE, dimaprok. These grandsons are both over 21 and pretty good athletes. One is in chiropractic school and the other is scheduled to graduate college next spring. Obviously, they don't get time to shoot very often. I'm just trying to make sure they have ammo when they do get time.