9mm with unique what a differens a coupel of 1/10s make

[mdevlin53]

loading 9mm 125 grn LRN with Unique. I loaded up test rounds starting at 4 grains and by tenths went up to 4.4 grains. the 4 grains shot a pattern like a shotgun 4.1 a bit better til I got to 4.3 a nice group and 4.4 started to open up again. It never cases to amaze me how small a change in powder weight can make such a big difference in group size. the best group was about 3 inches at 15 yards which is not great but I am fairly new to pistol shooting and the gun is brandy new as well. I am sure as I practice I can tighten this up a bit.

[JSnover]

Yup. One of the old-timers at my club told me years ago, 1 tenth probably won't change much. Bump it 2 tenths up or down if you want to see results. It is often wise to go in 1 tenth increments but you usually have to do it twice to see any real difference.

[runfiverun]

what really sucks is when that one tenth is the difference between shooting on top of your sight or behind it.
the one behind the sight is more accurate, but the one on top goes where you want the boolit to go in the field.
and there ain't no elevation adjustment to the sight settings.

[tazman]

what really sucks is when that one tenth is the difference between shooting on top of your sight or behind it.
the one behind the sight is more accurate, but the one on top goes where you want the boolit to go in the field.
and there ain't no elevation adjustment to the sight settings.

I been there. I have an auto that shoots like that. I hate to load a heavier slug just to raise the impact point but I may have to.

[fredj338]

It's more the relationship of the powder to the smaller case volume of the 9mm. Smaller changes will make a bigger diff there.

[Blackwater]

Hey Run, that's why they make files, doanchaknow? [smilie=l: I think we've all been there. LPA also makes some adj. rear sights designed for use with factory front sights, too. You might want to check them out. I really like mine. Big, wide, deep notch with heavy white outline. Even my tired ol' eyes can see those! Just a FWIW.

[MtGun44]

+1 on tiny case volume making the difference.

[tazman]

+1 on tiny case volume making the difference.

I have to agree with that also. I changed primer types from standard to magnum on one of my 9mm loads and it made a world of difference in group size.

[BenW]

I worked up a load for 9mm using 102 grain cast bullets. I found that at about middle of the road charges were the most accurate. But go 0.1 grain over and it was like a light switch. POI went up literally 20 ft at 50 yards. You could aim at the ground and almost miss.

I think 0.2 grains is not that big a deal when you have a rifle that takes 20-30 grains. But when you have a pistol where the difference between min and max charges is about a grain, 0.2 seems like a large chunk.

[Shiloh]

My load for that booiit is 4.1 gr. Unique.

Shiloh

[pappy4]

115 grn rn lead 5.9 grn acc #5 cci 500 primers win brass works for me.

[BABore]

Then I would pick another powder with more range between good and bad groupings. That is unless you plan to weigh each charge. I've yet to see a measure that will hold less than +/- 0.1 grains with Unique. AA #5 is almost a ball version of Unique.

[Blackwater]

NOW you're learning to load REALLY good ammo! It DOES often make a BIG difference.

[fecmech]

Then I would pick another powder with more range between good and bad groupings.
My sentiments exactly. That load is what I would call "too fussy". I have many good accurate handgun loads in various calibers and none of them depends on tenth of a grain accuracy with powder, 9MM included.

[Screwbolts]

Many good things have already been pointed out, the small 9mm case and all other small cases can also be very temperamental on seating depth even with light charges. Some powders are more sensitive to this, but be carful not to seat to deap, pressure can skyrocket just by seating a few thousands deeper.

Ken

[Calamity Jake]

Then I would pick another powder with more range between good and bad groupings. That is unless you plan to weigh each charge. I've yet to see a measure that will hold less than +/- 0.1 grains with Unique. AA #5 is almost a ball version of Unique.


I don't think there is an affordable scale out there is that accuracy tolerance is better than ± 0.1 grains, most are
± 0.2 grains.
So if your scale accuracy tolerance is .1 then you don't know if you really added .1 grain or .2 or none at all.

[Jayhawkhuntclub]

I have never found Unique's performance to vary much if off by a tenth of a grain or two. Which is good because it meters like ****. Not to sound rude, but... If your best groups are 3" at 15 yards, I have to think you are seeing more a variation in your performance and not that of the load. What is your sample size? If you're shooting dozens of groups and this trend is consistent, then I would agree. If you're only shooting a few groups with each charge, then I think your seeing a trend that is created by chance. In other words it is a correlation, but NOT a result of cause and effect.

[mdevlin53]

One thing here is that I am using Unique because that is the only pistol powder I have left. I much prefer titegroup but alas there is none to be found or any other choices at the moment. I shot sever 5 shot groups with each load and you are right much could be from my shooting style grip and stance. As I said I am new to pistol shooting but have done some research as to good practices and am getting better. I am using a Lyman 55 measure and checking it with a Dillon scale I tried very hard to keep the charges consistent and weighed each charge for these test rounds. The group sizes were pretty consistent and to try and see if I could be scientific I had my daughter load the pistol and not tell me what charge was in the gun. Finally what I was looking for was a load that grouped well that I could use to practice with. The comments have been great and I will keep trying to improve both my loading practices and my shooting skills thanks for the help.