I actually got a T&E set of each from Simunition and gave the following write up as a proposal, names removed:
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Proposal: Simunition AR15’s
Submitted by: Officer XXXX
At the request of Sgt XXXX, I did some research into Simunition platforms for the AR15 style of rifles. I contacted the company directly and learned that they offer two basic types of Simunition conversions.
The first type of Simunition conversion is the bolt replacement style. The kit comes with a bolt and bolt carrier that replaces the bolt and carrier inside the standard AR15. This converts the rifle to blowback design. The force of the cartridge firing works the bolt (like our pistols) instead of the expanding gas working the bolt (like a standard AR15).
The second type of Simunition conversion had a dedicated upper receiver that uses the standard 9mm marking cartridges we already stock for our Sig conversions. This system was also of blowback design.
The pros and cons of each system:
.223 Bolt Conversion:
Pros:permits use in any rifle which allows use of standard accessories, uses standard AR15 magazines, cheaper up front conversion cost
Cons:requires special .223 marking cartridges, can load and chamber standard .223 live rounds, higher velocity requiring additional protective equipment and longer stand off distance, can foul the barrel which is the barrel used for on duty use
9mm Upper Conversion:
Pros:permits use of ammunition we already stock, cannot accidentally chamber .223 or .40 live rounds, can be used with standard protective equipment
Cons:requires dedicated gun that isn’t exactly the same as the individual Officer’s rifle, requires special magazines, more expensive initial cost
Equipment compatibility:
The strongest argument for the .223 bolt conversion is that it allows an Officer to use his or her patrol rifle. The weight, barrel length, trigger, stock, sling, light, optic, etc. will all be identical to what the Officer uses on the street. You simply remove the exsisting .223 bolt and carrier out of the rifle and replace it with the Simunition bolt and carrier. This can be done by anyone that knows how to clean the AR15 rifle. The .223 bolt conversion also uses standard AR15 magazines.
The 9mm upper requires a dedicated weapon that won’t exactly match what each individual Officer uses on the street. It would not differ greatly as most patrol rifles are configured around a 16” barreled, collapsible stock AR15. The largest variation is with vertical foregrips, weapon mounted lights, and sighting systems.
Saftey:
The strongest argument against the .223 bolt conversion is that since you are using standard magazines and barrels, a live .223 round can be loaded, will feed from the magazine, and can be chambered. The .223 conversion bolt and ammo use a rebated case rim. This will, in theory, prevent the bolt from closing on a standard .223 round and will not allow the bolt to go fully into battery. While this should never allow a live round to fire, it isn’t as safe as using a gun that cannot chamber a live round. The .223 bolt conversion also requires additional protective equipment and greater stand off distances for engagement due to the higher velocity of the round.
The 9mm upper conversion cannot chamber a live .223 or .40 round. The velocity of the 9mm round in a rifle platform allows us to use it at the same distances and with the same protective equipment as we currently use the Sig conversions.
Another safety consideration is that additional protective equipment is required for use with the 5.56 cartridges. A throat protector and a groin protector would be required for anyone participating in training while the 5.56 rifles were being used.
Cost:
As stated above, the 5.56 bolt conversion is less expensive than the 9mm upper receiver conversion. The standard 5.56 bolt conversion lists at $289 per unit while the 9mm upper (with 16” barrel) lists at $684. This is a difference of $395 per unit. There would also be an additional cost per rifle for spare magazines ($38 per magazine) and a rear sight ($70 per rifle). Assuming we would want 2 extra magazines per rifle this would increase the price difference to $541 per rifle.
The offset to this is the fact that the 5.56 ammo is more expensive. The 5.56 ammo is $644 per thousand rounds while the 9mm is $515 per thousand. This is a difference of $129 per thousand rounds of ammunition. The extra cost per rifle for the 9mm upper conversion would break even at approximately 4194 rounds fired and would be less expensive overall after that point. While 4194 rounds is a significant number, with our current training schedule we would reach that number in just a few years of service from the conversions. The other consideration is that the 9mm marking cartridges are already ordered and stocked for our Sig conversions while the 5.56 cartridges would require separate inventory.
Another cost point to consider is that the 5.56 cartridges require additional protective equipment. They require throat and groin protection ($38 for throat, $50 for groin). We would also have to purchase more than one per rifle as everyone in a scenario where a rifle is used would required the additional equipment. Assuming we purchased 10 of these items (a minimum for active shooter or SWAT training) that would be an additional purchase of $880 for just protective equipment. It would also be another item that would need to be transported and accounted for every time we did Simunition training.
Testing:
I was able to procure a test and evaluation example of both the 5.56 bolt conversion and the 9mm upper receiver conversion. Officer XXXX and I took both of the units to the range for testing. We obtained the following results:
5.569mm AR 9mm Sig
Avg. Muzzle Velocity (fps):617.9499.2420.2
Avg Accuracy (10yds): 3.5”2”3.5”
Impact (from POA at 10yds):1.5” high 2.5” low 12” low
Avg Accuracy (25yds): 5”7”N/A
Impact (from POA at 25yds):Zeroed12” low N/A
Avg Accuracy (50yds): 8”18”N/A
Impact (from POA at 50yds):4” low48” low N/A
The first thing to note is the substantial increase in muzzle velocity from the 5.56 rounds. The average velocity of the 5.56 was approximately 200 feet per second faster (almost 50%) than the average velocity of the 9mm round from the Sig conversion. This demonstrates the need for the additional protective equipment should the 5.56 conversion be used. It should also be noted that the 9mm AR conversion showed a velocity increase with the same ammunition over the Sig platform due to the extended barrel length (average increase of approximately 80 feet per second or 20%).
The extended range of the 5.56 conversion is evident from the figures above and is mostly due to increased velocity. The 9mm round from the pistol were unable to pattern at 25 yards due to inaccuracy and low velocity. The 9mm did much better from the rifle but was still far exceeded by the 5.56.
As for reliability, we fired several full magazines of both 5.56 and 9mm round through their respective platforms. While the test and evaluation parts were dirty and uncleaned from the last user, they both functioned flawlessly. In approximately 100 rounds of each, neither rifle experienced a single malfunction. This included rapid fire sequences firing full magazines of ammunition.
While it is unlikely that we would never see a malfunction from either platform, this suggests that the reliability of the rifle conversions is significantly better than that of the Sig conversions we currently use.
One note of caution: the 5.56 conversion bolt can be used in any AR15 platform. Many rifles use different length gas systems and/or different buffer and spring configurations. It is possible that the bolt conversion would not function this well with every combination that is used by our Rifle Operators. We simply didn’t have enough test ammunition to evaluate the conversion in every type of AR15 rifle.
After our range testing, the 9mm upper conversion was used in our active shooter/Officer down rescue training. The response from Officers that used the conversion was overwhelmingly positive. All considered it a valuable training aide and no problems were experienced during the scenarios with the equipment. We were unable to use the 5.56 conversion in this training due to lack of ammunition and the fact that we did not have the additional protective equipment.
Conclusions:
Both the 5.56 and the 9mm platforms would serve well for training purposes. Both have the respective advantages and disadvantages but overall Officer XXXX and I believe that the 9mm conversion is preferable for our uses. The fact that we were unable to use the 5.56 during training scenarios due to ammo shortage and protective equipment pinpoints the major limitations of the 5.56 conversion. If we have ammuntion for the Sig conversions, we have ammunition for the 9mm AR conversion. If we have protective equipment for the Sig conversions, we have protective equipment for the 9mm AR conversions. It is also apparent that while the 5.56 conversion would save some up-front cost, over several years the 9mm conversions will prove to be less expensive due to ammunition costs. Finally, the added safety of it being physically impossible to load and chamber a live round in the 9mm conversion makes it the better choice.
Proposal:
I propose that the department purchase two 9mm upper receiver conversions for the AR15/M16 platform (P/N 5306585 $684/ea). Along with this purchase, I propose we purchase 4 additional magazines (P/N 5308310SP $38/ea) and 2 rear sights (Brownells P/N 231-000-030 $66.60/ea). We would also need to dedicate 2 of the DRMO M16 rifles for training use. Since we already have the ammunition and protective equipment this would be all the required items needed to incorporate these conversions into force on force Simunition training. If funds allow I would like to equip these rifles with collapsible M4 style stocks (Brownell’s P/N 080-000-545 $65/ea) and 3 point slings (Brownell’s P/N 100-000-377 $18/ea) to set the rifles up as close as possible to the standard patrol carbine in use by our Department.
The total expenditure would be $1653.20 for the uppers, magazines, and sights with an additional $166 for stocks and slings ($1819.20 total).