Dangers using cast load data for plated or fmj rifle bullet reduced loads.

[arakboss]

I use Unique / Universal in 308 and 30-30 with 110gr plated rounds from Precision (basically 30 carbine projectiles).
Over on LRH, search reduced loads and there's another shooter there who experienced a detonation with a reduced load that had been thought to be OK.
Point being, you cannot just use any powder.
Some powder burn is affected by surface area, and will be much faster with 50% case fill or less because there's a lot more exposed surface area - like lighting gasoline in a saucer vs a test tube. One goes FOOF! and the other has a bit more control to the flame.
Some powders are more affected by pressure, and burn better at that pressure.
General rule of thumb with most powders is don't be below 80% case fill and not a good idea if you're above 105%. Some are renown for nasty pressure spikes when overfilled.

I am planning on following Lymans cast bullet data, hopefully they took the detonation problem in to account when developing their loads. I don't think switching out a FMJ bullet in place of a cast bullet would increase the likelihood of a detonation?

 

[P7M13]

I am planning on following Lymans cast bullet data, hopefully they took the detonation problem in to account when developing their loads. I don't think switching out a FMJ bullet in place of a cast bullet would increase the likelihood of a detonation?

Plated bullets, i.e. electroplated with a layer of copper one or two molecules thick, would not pose a problem. Full jacket is a whole 'nuther story.
Pure lead is soft, hard cast is what, ~14 Brinnell? Copper jacket is what, ~28? The difference you'd experience is the change in pressure spike as the bullet deforms to fit down the bore, i.e. obturation.

Edit - when it comes to copper vs cast, I'm a relative noob. I can think of a few others on NWFA who are much, much more knowledgeable on the subject of cast vs. jacketed. i.e., they have been casting longer than I've been reloading, etc. Have you visited cast boolits?

 

[Certaindeaf]

That is a warning applied to all powders .

Yep, and therfore would not be an actual approved reduced load by definition.
This isn't about what can physically be shoehorned into a case.

 

[Capn Jack]

Down load a burn chart if you have questions about powder comparisons and be very careful with any powder you can get a, "double charge" into a case, like BullsEye, etc.

 

[arakboss]

Plated bullets, i.e. electroplated with a layer of copper one or two molecules thick, would not pose a problem. Full jacket is a whole 'nuther story.
Pure lead is soft, hard cast is what, ~14 Brinnell? Copper jacket is what, ~28? The difference you'd experience is the change in pressure spike as the bullet deforms to fit down the bore, i.e. obturation.

Lyman claims a BHN of 100 for gilding metal. I would take in to consideration that many of the cast bullets Lyman used in their test loads were a gas checked variety. They don't say on the load data pages as to whether they used a gas check or not but I will assume they did where the bullet variety is a gas check style bullet. Some max loads they developed are near jacketed load velocities and it's hard to imagine they did it without gas checked bullets.

I will begin at the starting load recommendations and very carefully work my way up to an accurate load and I will avoid loads that are listed near case velocity limits (i.e. max loads).

 

[arakboss]

Down load a burn chart if you have questions about powder comparisons and be very careful with any powder you can get a, "double charge" into a case, like BullsEye, etc.

I am going to make a gauge like the guy had in the video to check for overloads in bottleneck cases. He addressed the overcharge issue at the 22:10 mark.

 

[RVTECH]

I use Unique / Universal in 308 and 30-30 with 110gr plated rounds from Precision (basically 30 carbine projectiles).

Same here with 10 grains of Unique. Incredibly accurate.

 

[Certaindeaf]

Lyman claims a BHN of 100 for gilding metal. I would take in to consideration that many of the cast bullets Lyman used in their test loads were a gas checked variety. They don't say on the load data pages as to whether they used a gas check or not but I will assume they did where the bullet variety is a gas check style bullet. Some max loads they developed are near jacketed load velocities and it's hard to imagine they did it without gas checked bullets.

I will begin at the starting load recommendations and very carefully work my way up to an accurate load and I will avoid loads that are listed near case velocity limits (i.e. max loads).

I thought your question was whether jacketed bullets could be used using reduced load lead bullet data, not max load lead bullet data.

 

[arakboss]

I thought your question was whether jacketed bullets could be used using reduced load lead bullet data, not max load lead bullet data.

That is confusing. I should rephrase the question and ask if it is dangerous to use the cast load data listed in the Lyman cast bullet handbook with an FMJ bullet? Lyman doesn't really list any loads as reduced in their handbook.

 

[03A3Sporter]

It is not dangerous and I have used it before with FMJ projos . a lot of Lyman loads with gas checked cast bullets can be fairly speedy.

Concerning cast all the load information Lyman lists is for bullets made with Lyman No2 alloy. I think it is also worth nothing that you can make a cast lead bullet too hard , the reason this is a problem has to do with obtuiration .

That is confusing. I should rephrase the question and ask if it is dangerous to use the cast load data listed in the Lyman cast bullet handbook with an FMJ bullet? Lyman doesn't really list any loads as reduced in their handbook.

 

[arakboss]

It is not dangerous and I have used it before with FMJ projos . a lot of Lyman loads with gas checked cast bullets can be fairly speedy.

Concerning cast all the load information Lyman lists is for bullets made with Lyman No2 alloy. I think it is also worth nothing that you can make a cast lead bullet too hard , the reason this is a problem has to do with obtuiration .

Thanks and I found the Blue Dot 223 load info from Seafire. I might be able to use the blue dot in 22-250 too.

I love this forum.

 

[03A3Sporter]

Glad you found it ! Blue Dot is also useful for 243 and other similar cartridges .

Thanks and I found the Blue Dot 223 load info from Seafire. I might be able to use the blue dot in 22-250 too.

I love this forum

 

[arakboss]

Glad you found it ! Blue Dot is also useful for 243 and other similar cartridges .

That's great I have a CVA Hunter in 243 that might get the blue dot loads too.

 

[gmerkt]

I used to load jacketed bullets at reduced loads. My guidance was DuPont (later IMR) and Speer published data. I used the recommended faster rifle powders, like SR 4759, IMR 4227 and IMR 4198. I wasn't using them for hunting so expansion was a non-issue in my case. IMR 4895 is also a candidate for reduction down to a certain point, you can read about this elsewhere on the internet.

I liked the DuPont / IMR reloading pamphlet that they used to publish every few years. They had formulated loads as widely across their range of powder offerings as possible. Meaning, you could use nearly every one of their rifle powders for any given rifle cartridge, with exceptions. The Speer reduced charge data specifically noted it as such.

For a while, I experimented with very reduced loads of Red Dot as propounded by Ed Harris. Using cast bullets, but some plated bullets would likely be okay for this. I also experimented with small charges of 2400. This practice has its limitations. For one thing, some loads would be adequate for bullet propulsion but not for sealing the gas in the cartridge case. In my experience.

Since SR 4759 is no longer available for reduced rifle loads, another good one is Accurate Arms 5744.

 

[dangerranger60]

This is what I was hoping to here. I was worried that the FMJs would have more friction sliding down the bore and potentially raise pressures. I will begin at the start loads and work my way up. All these loads will be for plinking so expansion isn't a concern.

I think the difference is going to be that cup and core FMJ bullets are sized slightly smaller to make up for the "jacket" being a harder material. FMJ is usually sized .355 [ for 9mm] and cast or plated are sized .356 or .357.
In reduced loads that are not below the min charge I would not have a problem using either bullet. Where I would expect problems would be in pushing either bullet beyond its expected use. DR

 

[arakboss]

I think the difference is going to be that cup and core FMJ bullets are sized slightly smaller to make up for the "jacket" being a harder material. FMJ is usually sized .355 [ for 9mm] and cast or plated are sized .356 or .357.
In reduced loads that are not below the min charge I would not have a problem using either bullet. Where I would expect problems would be in pushing either bullet beyond its expected use. DR

I will trust your info based on your username alone

That makes great sense about jacketed bullets being a thousandth smaller diameter, helping to equalize friction in bore.

 

[CLT65]

Follow published loads only. Never deviate outside of published limits. Don't use "homebrews" from internet forums or loads you heard were good from people at the LGS. This isn't a batch of cider.

As someone who's been tinkering for 30+ years, I have to disagree. There are plenty of things that can be done safely that aren't published in the manuals, so long as you really know what you're doing and understand what's involved. I consider them advanced techniques.

If you don't have a solid grasp of what you're doing and how to do it safely, then by all means, published loads only.

 

[dangerranger60]

As someone who's been tinkering for 30+ years, I have to disagree. There are plenty of things that can be done safely that aren't published in the manuals, so long as you really know what you're doing and understand what's involved. I consider them advanced techniques.

If you don't have a solid grasp of what you're doing and how to do it safely, then by all means, published loads only.

If we never colored outside the lines there would not be much data for others to follow!
I have been shooting a 6.5x55 Mauser since the 80's. There was not much data to be had until the 6.5 CM took off. They have very similar pressure limits, and use very similar bullets. By using the CM's data, and starting from a reduced load I have found several that work well for me that are not in any book [ in 6.5x55 Mauser].
Try finding lead free loads for the Mauser.
I also shoot old Spanish pistols in 9mm Largo. You wont find much in any handloading books. But the pressures they work at are up to 9mm+P , and use a 38 Super case. With a little creativity I can turn out safe loads, But you won't find them in any data books. DR

 

[41mag]

All these loads will be for plinking so expansion isn't a concern.

why use FMJ at all if expansion isn't required?

 

[arakboss]

why use FMJ at all if expansion isn't required?

It's what I generally have on hand and mostly for the desire to experiment. I don't really cast myself even though I own limited equipment to do so, lee pot, a few molds, some lead, gas checks, lee sizer dies, etc.

22 caliber cast bullets are hard to find and cost may be on par with cheaper fmj projectiles of which I have many thousands on hand. I have purchased cast bullets, mostly in pistol calibers and I will continue to use those but I have switched to buying mostly plated or cheap FMJ bullets for pistols too. I will still make an occasional purchase of cast (preferably coated) when a great deal comes along but I find plated or fmjs cleaner to work with over uncoated lead bullets.

My mind gets bored easily so thinking about new to me or less conventional ideas keeps my mind occupied. One day I will be happy sitting in a a easy chair watching reruns of All In The Family but I am not there yet.