115 grain for training and 147 for competition

[chinnerj]

Question: anyone here use a different grain bullet for training than for competition? I was thinking for next year I might order all of my training rounds in 115 and stick with 147 for my competition loads in order to save money. An important point I want to make is that I wouldn't plan on changing the charge weight of the powder as I would like to keep the felt recoil the same. I understand that the 115 grain loads would be way under PF, but wouldn't the recoil be the same since it is mostly determined by the charge weight and seating depth of the bullet? Just trying to find ways to save a little money here and there since there is a considerable difference between buying 115 vs. 147 grain projectiles.

[Khaot1c]

If the recoil pulse is significantly different then you can expect a point of impact shift. That introduces quite a few variables in your training that may lead to conscious thought on match day such as remembering holds or adjusting to the timing or feel of your match ammo.

 

 

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[MikeBurgess]

11 minutes ago, chinnerj said:

Question: anyone here use a different grain bullet for training than for competition? I was thinking for next year I might order all of my training rounds in 115 and stick with 147 for my competition loads in order to save money. An important point I want to make is that I wouldn't plan on changing the charge weight of the powder as I would like to keep the felt recoil the same. I understand that the 115 grain loads would be way under PF, but wouldn't the recoil be the same since it is mostly determined by the charge weight and seating depth of the bullet? Just trying to find ways to save a little money here and there since there is a considerable difference between buying 115 vs. 147 grain projectiles.

Most 115g loads will make PF just fine in most guns, I ran 115 Federal aluminum case stuff at one and Blazer Brass at another L2 match and both times made PF with a decent margin (130ish) 

That said try shooting some and see how it feels, then try mixing some with your 147s in a mag and shoot a drill, you may be surprised to see how little difference there is in what the sights are doing. 

[HesedTech]

Yes you can use the same bullet in a lighter weight to save a few dollars, as long as the powder charge is the same.  You won’t notice any real difference in recoil, but you may see a difference in accuracy.

 

The real question is how many $ will you save over the extra work of keeping the two loads separated and not accidentally mixing them and then get sent to open at a major match?
 

 

[zzt]

I always practice with what I'll shoot in matches.

[stick]

You will see a point of Aim, point of impact change between the two loads.  I'm lost with your reason to use two different loads.  Using the same load for practice and competition is pretty much standard. 

[Hi-Power Jack]

3 hours ago, chinnerj said:

 I might shoot training rounds in 115 gr and stick with 147 for my competition loads to save money. 

 

Are you a D or C shooter ?  Then you might save a few $$$ that way.  Doubt a B shooter, working

towards an A card, would want to do that.

 

How many rounds/year are you shooting ?

 

Are you using coated lead bullets to save money ?

[MikeyScuba]

2 hours ago, zzt said:

I always practice with what I'll shoot in matches.

 

That about sums it up.  I try to make practice as close as possible to match conditions.

[Joe4d]

umm, WHY ? you wont save much..  train like you fight,, Look for deals. I suspect you could go cheap cast 147's for practice and use Wolf primers,,, then for match ammo go with fed or win primers and 147 coated or jacketed for match ammo. Get same recoil and POI,, save a few bucks

[superdude]

Recoil won't be the same if you use the same powder charge. The lighter bullet will have less recoil.

 

What affects recoil: bullet weight, velocity, powder charge weight.

 

The lighter bullets will end up going the same speed as the heavier bullets, or more likely they will be slower, and either of these will reduce recoil. 

 

Example:

 

powder charge 5 grains, velocity 1000 fps, 2.5 lb gun;

 

115 grain bullet = 1.90 ft lbs recoil

 

147 grain bullet = 3.03 ft lbs recoil

 

[RePete]

14 hours ago, HesedTech said:

 

 

The real question is how many $ will you save over the extra work of keeping the two loads separated and not accidentally mixing them and then get sent to open at a major match?
 

 

 

This^^^^^^^^^

 

At at PPC match, we had a guy who used 2 loads. 7 and 15 yards and 25 and 50 yards.  

 

The powder charges were 3.0gr and 1.7gr.

 

He shot the 7 and 15, shot the 25 and then proceeded to to shoot the 50.  When we went down to score his target was clean (I was scoring his targets).  I turned around and you could see the impact marks in the ground.  From that day he quit using 2 loads.

[Demp223]

No. Waste of time reloading two different loads and keeping them separated. Plus they perform differently. Buy in bulk to save money and load what you’re going to shoot. 

[RGA]

What the others said. Train as you fight, fight as you train.

 

Don't introduce unnecessary risks. Murphy is always watching.

[Stuey]

I train with what i shoot in competition. The cost between 115 and 147 is not worth the training difference.


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[Jim Watson]

On ‎11‎/‎1‎/‎2019 at 2:21 PM, chinnerj said:

but wouldn't the recoil be the same since it is mostly determined by the charge weight and seating depth of the bullet?

 

No.

Power Factor is a momentum value, just not in scientific or engineering units, and recoil is a momentum balance.  Mass X Velocity. 

[HesedTech]

 

 

8 hours ago, Jim Watson said:

but wouldn't the recoil be the same since it is mostly determined by the charge weight and seating depth of the bullet?

 

 

I didn't say they would not be a difference in recoil impulse using math (yes there's a web app that will calculate that for people). I said, "you won't notice any real difference."

Perception of recoil is probably more important than the actual amount.

 

On 11/1/2019 at 1:56 PM, HesedTech said:

You won’t notice any real difference in recoil, but you may see a difference in accuracy.

[Yondering]

On 11/1/2019 at 7:46 PM, superdude said:

Recoil won't be the same if you use the same powder charge. The lighter bullet will have less recoil.

 

What affects recoil: bullet weight, velocity, powder charge weight.

 

The lighter bullets will end up going the same speed as the heavier bullets, or more likely they will be slower, and either of these will reduce recoil. 

 

Example:

 

powder charge 5 grains, velocity 1000 fps, 2.5 lb gun;

 

115 grain bullet = 1.90 ft lbs recoil

 

147 grain bullet = 3.03 ft lbs recoil

 

 

This. 

 

The lighter bullet will have less recoil, and it is definitely noticeable between 115gr and 147gr bullets. 

POI will be different as well, in most guns. YMMV of course. 

Edited November 4, 2019 by Yondering

[B_RAD]

Shoot all 115 gr. 

 

Doesn't matter. 

 

I just saved you a bunch of money. You're welcome. 

[hankdiesel]

For minor 9mm I shoot all 147s...train with what you plan to compete with.

[tomv]

On 11/1/2019 at 3:21 PM, chinnerj said:

Question: anyone here use a different grain bullet for training than for competition? I was thinking for next year I might order all of my training rounds in 115 and stick with 147 for my competition loads in order to save money. An important point I want to make is that I wouldn't plan on changing the charge weight of the powder as I would like to keep the felt recoil the same. I understand that the 115 grain loads would be way under PF, but wouldn't the recoil be the same since it is mostly determined by the charge weight and seating depth of the bullet? Just trying to find ways to save a little money here and there since there is a considerable difference between buying 115 vs. 147 grain projectiles.

Recoil is based on momentum, Mass x Velocity. Also known as power factor. The 115 bullet with the 147 bullet powder charge will have significantly less mass resulting in lower pressure resulting in lower velocity. So both mass and velocity will be reduced and there will be a noticeable difference in recoil force. If you play with the charge to get the same power factor for both loads you will still notice a difference in how the gun runs. The slide will cycle much faster with the 115 load.

 

I agree with bthe comment that it's best to practice with what you're using for competition.