Is there much difference to load using different but same grain bullets

[Davey Boy]

Is there much difference to load using different but same grain bullets?

Say I loaded up some Sierra #2115 150 Grn. for my .308, got a good load for it, then changed to a Sierra #2135 also 150 grns. using the same load.

Would I have to change much in regards to powder or seating depth or would it be a good starting point to pursue and fine tune the hunting round #2135 from the FMJBT #2115.

Reason why is the 2115's are .38 cents each and 2135's are .47 cents up here in the cold frozen north.

I'm a novice at reloading!

 

[dstoenner]

Probably won’t be optimum. The 2 bullets have different bearing surface which would cause velocity changes and different front ends so seating would be different.

you could try but why chance it. I would just buy the bullet i want to shoot and get the load right. How much do you want to pay to maybe chase your tail

David

 

[Davey Boy]

Reason I'm doing this is because I got a lot of reloading supplies from a fella who was getting out of guns, so I have many types of powder, bullets, cases and primers.
Want to work up a load with the cheaper bullets FMJ's then extrapolate that load to the various hunting bullets that I have.

 

[6ShotsOr5?]

Reason I'm doing this is because I got a lot of reloading supplies from a fella who was getting out of guns, so I have many types of powder, bullets, cases and primers.
Want to work up a load with the cheaper bullets FMJ's then extrapolate that load to the various hunting bullets that I have.

It might be okay within a few 100 yds on deer, but if you are shooting longer or targeting smaller critters it probably will give accuracy that you may not be too happy with.

 

[Davey Boy]

It might be okay within a few 100 yds on deer, but if you are shooting longer or targeting smaller critters it probably will give accuracy that you may not be too happy with.

Yes thank you that's what I wondered. Just trying to save a bit of time and materials as I do ladder testing then OCW testing, so thinking that the 2 bullets would be close to each other regarding the load for one of them. Realize may have to tinker a bit, but most of the data for one could be a good starting point for another, changing nothing but the bullet.

 

[6ShotsOr5?]

Yes thank you that's what I wondered. Just trying to save a bit of time and materials as I do ladder testing then OCW testing, so thinking that the 2 bullets would be close to each other regarding the load for one of them. Realize may have to tinker a bit, but most of the data for one could be a good starting point for another, changing nothing but the bullet.

You’ll probably have a zero shift, and also you need to know that everything might be fine with one bullet, but you could be over pressured when you just change the bullet and keep the other factors the same.

 

[Davey Boy]

I kind o

You’ll probably have a zero shift, and also you need to know that everything might be fine with one bullet, but you could be over pressured when you just change the bullet and keep the other factors the same.

I kind of rely on Quick Load and my Labradar to check a load that I have versus trying a new load. I'm not usually using max loads anyway, but yes I do watch for pressure.

 

[Ned Ludd]

Unless the base-to-ogive (BTO) dimensions on the two bullets are radically different, you should probably end up reasonably close to the same charge weight for a given velocity, but optimal seating depth may or may not be close. The only way to know for sure is to work up the load. You should have some idea of where to start in terms of charge weight based on your previous load. You could reduce that charge weight by 2 to 3% (for safety reasons) and start your ladder and/or OCW from there. It should be pretty obvious if the new bullet is giving comparable velocity for a given charge weight, but the testing should also identify at what charge weight the new bullet wants to shoot, regardless of whether it is the same charge weight as the previous bullet/load, or slightly different. When you get to a seating depth test, you're better off testing a relatively wide window, rather than focusing in on the seating depth at which the other bullet tuned in. The new one may tune in similarly, but it could also be very different, so you don't want to "miss" the optimal seating depth for the new bullet by testing over too narrow a window.

 

[Davey Boy]

Yes I understand. Using QL I would compare the 2 loads for velocity, pressure, powder, and seating depth. I have the Velocity from my Labradar, so could use that to see if I could, using QL to verify about the same numbers for the new load, staying well away from max pressures. Also have GRTools and 3 manuals and several online load manuals to compare and stay within safe limits. I realize I may have to go above and below the powder weight of my known good load by about a 3 grain spread (1.5 either way) so will start lower get the weight pinned down and then try some seating adjustments.
Working up a load originally took many trips, time and supplies, hopefully this way I can use less to get a new load from the old details.

 

[farmerjohn]

Look on the bright side of what you are doing. Practice is practice, all of the disciplines involving the art of shooting don't involve pulling the trigger. Working up new loads and keeping good notes is a good learning experience for anyone, I don't care how much experience you have. I'm 75 and learn something new on a regular basis and I've been reloading since the 50s. Have a good time and see what you learn, that's my two cents worth, John

 

[Davey Boy]

Oh don't get me wrong I love practice, but my problem is that I can't get out that often so am in a way trying to find small safe shortcuts to a good load. I love learning all about reloading,cleaning and trying to get the best I can with what I've got.

 

[K22]

In my experience the selection of the bullet is the single most influential factor affecting performance assuming you're using a powder suitable to the caliber. So changing bullet types / brands etc. even though the same weight can have a significant impact on performance.

For example, my Rem 700, 308, with IMR 4064, shoots the 150 grain Sierra Pro Hunter (#2130) in 1/2 moa groups where as the 150 grain Sierra Game King (#2135) doesn't group nearly as well. The former being a flat base and the latter and boat tail. However either bullet is accurate enough to take a deer at the ranges I normally have shot opportunities.

Unfortunately, many times its a trial and error process to find optimum load. One of the concepts I adopted several years ago to save on component costs and load development / bench testing time, which I hate, is to develop standards for my various rifles. So once I hit a load that meets that standard I can proceed to do what I enjoy most, hunting deer, varmints, and predator and practical ranges sessions shooting off my shooting sticks.

For me, I strive for about 1/2 moa for my varmint and predator rifles and 1 moa for my deer rifles. These standards are not absolute but it gives me a targeted group size. Truth is, a few tenths difference in group size makes little difference in field performance; it's more about marksmanship under field conditions.

 

[RegionRat]

The more you stay close to cartridges and guns that have lots and lots of background and history... the easier it is to find safe shortcuts, we call them Pet Loads. You won't have too much trouble with traditional military surplus rounds like the 30-06, 308, 5.56, etc. since they have also been used for competition and are very popular to date.

 

[YEW PLUCKER]

Is there much difference to load using different but same grain bullets?

Say I loaded up some Sierra #2115 150 Grn. for my .308, got a good load for it, then changed to a Sierra #2135 also 150 grns. using the same load.

Would I have to change much in regards to powder or seating depth or would it be a good starting point to pursue and fine tune the hunting round #2135 from the FMJBT #2115.

Reason why is the 2115's are .38 cents each and 2135's are .47 cents up here in the cold frozen north.

I'm a novice at reloading!

It is an interesting question. I haven't done a lot of this, but back in 1994, I loaded up a bunch of .308's with 168 grain SMK's, and then for giggles, I loaded up some Speer 168 HPBT's using the same powder charge and seating depth.

It is anecdotal and coincidental, but I got near exact same performance from both loads. At 100 Yards, both loads would put all shots into one hole as long as I didn't shoot the group too fast. I could cover both groups with a nickel.

The rifle was an early Remington PSS with an HS stock. When I would fire fast and hot, the groups would disperse laterally, which I found curious. A close friend, who had instructed at Range 37 told me that the original M24's showed the same lateral dispersion tendency when fired hot.

 

[searcher]

You will have to experiment to see what your rifle will do. As others suggested, you will likely encounter a shift in impact - and likely either better or worse accuracy. Best to start at the bottom of the powder chart and work up - if not for safety - do it so you don't miss the accuracy sweet spot for that new bullet. I'm not downplaying the safety aspect. I always start at LEAST half way down.

 

[piie]

I’ve also wondered as much: were convinced that any change in component would automatically result in a change of load, especially bullets. But then I saw a Hornady Load manual and my eyeballs melted... Still hoping for someone to clarify/explain- don’t have the entire manual - only some pages for specific calibers.

 

[GeoffreyKolbe]

Is there much difference to load using different but same grain bullets?

Say I loaded up some Sierra #2115 150 Grn. for my .308, got a good load for it, then changed to a Sierra #2135 also 150 grns. using the same load.

Would I have to change much in regards to powder or seating depth or would it be a good starting point to pursue and fine tune the hunting round #2135 from the FMJBT #2115.

Reason why is the 2115's are .38 cents each and 2135's are .47 cents up here in the cold frozen north.

I'm a novice at reloading!

Short answer - no. There might be some small differences in pressure and muzzle velocity, but not enough to make what was a safe load dangerous, or miss a target where you were hitting the middle.

Long answer - It can make a difference if there are significant differences in bullet density, where for example you exchange a copper jacketed lead bullet with a bronze solid of the same weight. The bronze solid will be longer than the denser lead jacketed bullet and so will mean there is less usable case capacity for the same COAL. The same load in less usable case capacity will lead to a bigger bang. What was a 'frisky' load, could become dangerous.

 

[cem]

Is there much difference to load using different but same grain bullets?

As everybody correctly notes for the example given, both cup and core from the same maker there won't be much difference. Given the difference between full metal jacketed with a sharp point and a round nosed soft point I would expect optimal seating depth to vary a little bit or maybe a lot but if properly aligned in a nicely throated and aligned chamber I would expect close enough for practical purposes if not for best possible accuracy. That is the more runout varies the more I expect accuracy to vary.

But also as noted I limit this to cup and core bullets. Bullets of different materials and hardness can and mostly do give quite different results -- including issues like a running start on the rifling for monometals and host of possible issues.

 

[Texas10]

Here is a 9 shot initial load development I tried recently with excellent results. Since you have a ball park charge weight but are changing bullet brands this will save precious components. This is for a bolt gun, not an autoloading type and of course if using magazine feed, you'll need to know your max length.

Start by finding the hard jam dimension by seating the new bullet long in an empty case and chambering it by forcing the bolt closed. Then working back from that, pick 3 shorter dimensions. I used -.020 off hard jamb, -.040 and -.060. All of these fit the magazine of the rifle being tested.

Then pick 3 charges that bracket your previous charge, differing by say, 1 gn. in your .308.

Load the three different charges for each bullet seating depth and shoot them into three targets labeled by seating depth. I placed 3, two inch dots on a single page of heavy copy paper and shot them at 210 yds. Keep track of where each shot lands, or use a sharpie to color the bullets differently, such as black for the lowest charge wt, blue for the next and red for the highest charge. They'll leave tell tale colors on the targets.

What you're looking for is a seating depth that is tolerant to charge weight variation. Watch for pressure signs, especially as you near the longest seat depth where the bullet is "in the lands".

When I did this for a 300 PRC, loads 1 and 2 of the -.060 loads went into the same hole with load 3 (highest) just an inch off horizontally at 210 yds. This showed the shortest of the seating depths was most tolerant of charge weight changes while the -.040 loads shot larger, more vertical and the -.020 was worst with very large spread.

This will easily get you within a minute of deer, but will need fine tuning for ELR or target work.

 

[David Milisock]

Is there much difference to load using different but same grain bullets?

Say I loaded up some Sierra #2115 150 Grn. for my .308, got a good load for it, then changed to a Sierra #2135 also 150 grns. using the same load.

Would I have to change much in regards to powder or seating depth or would it be a good starting point to pursue and fine tune the hunting round #2135 from the FMJBT #2115.

Reason why is the 2115's are .38 cents each and 2135's are .47 cents up here in the cold frozen north.

I'm a novice at reloading!

Who knows! Just rework the load.